{"id":21715,"date":"2016-02-17T22:26:45","date_gmt":"2016-02-17T22:26:45","guid":{"rendered":"http:\/\/www.mometrix.com\/academy\/?page_id=21715"},"modified":"2026-03-26T11:50:59","modified_gmt":"2026-03-26T16:50:59","slug":"introduction-to-types-of-triangles","status":"publish","type":"page","link":"https:\/\/www.mometrix.com\/academy\/introduction-to-types-of-triangles\/","title":{"rendered":"Introduction to Types of Triangles"},"content":{"rendered":"\n\t\t\t<div id=\"mmDeferVideoEncompass_Gujeh2yhPz0\" style=\"position: relative;\">\n\t\t\t<picture>\n\t\t\t\t<source srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/01\/circle-play-duotone.webp\" type=\"image\/webp\">\n\t\t\t\t<source srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/01\/circle-play-duotone.png\" type=\"image\/jpeg\"> \n\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" loading=\"eager\" id=\"videoThumbnailImage_Gujeh2yhPz0\" data-source-videoID=\"Gujeh2yhPz0\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/01\/circle-play-duotone.png\" alt=\"Introduction to Types of Triangles Video\" height=\"464\" width=\"825\" class=\"size-full\" data-matomo-title = \"Introduction to Types of Triangles\">\n\t\t\t<\/picture>\n\t\t\t<\/div>\n\t\t\t<style>img#videoThumbnailImage_Gujeh2yhPz0:hover {cursor:pointer;} img#videoThumbnailImage_Gujeh2yhPz0 {background-size:contain;background-image:url(\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/02\/358-types-of-triangles-3.webp\");}<\/style>\n\t\t\t<script defer>\n\t\t\t  jQuery(\"img#videoThumbnailImage_Gujeh2yhPz0\").click(function() {\n\t\t\t\tlet videoId = jQuery(this).attr(\"data-source-videoID\");\n\t\t\t\tlet helpTag = '<div id=\"mmDeferVideoYTMessage_Gujeh2yhPz0\" style=\"display: none;position: absolute;top: -24px;width: 100%;text-align: center;\"><span style=\"font-style: italic;font-size: small;border-top: 1px solid #fc0;\">Having trouble? <a href=\"https:\/\/www.youtube.com\/watch?v='+videoId+'\" target=\"_blank\">Click here to watch on YouTube.<\/a><\/span><\/div>';\n\t\t\t\tlet tag = document.createElement(\"iframe\");\n\t\t\t\ttag.id = \"yt\" + videoId;\n\t\t\t\ttag.src = \"https:\/\/www.youtube-nocookie.com\/embed\/\" + videoId + \"?autoplay=1&controls=1&wmode=opaque&rel=0&egm=0&iv_load_policy=3&hd=0&enablejsapi=1\";\n\t\t\t\ttag.frameborder = 0;\n\t\t\t\ttag.allow = \"autoplay; fullscreen\";\n\t\t\t\ttag.width = this.width;\n\t\t\t\ttag.height = this.height;\n\t\t\t\ttag.setAttribute(\"data-matomo-title\",\"Introduction to Types of Triangles\");\n\t\t\t\tjQuery(\"div#mmDeferVideoEncompass_Gujeh2yhPz0\").html(tag);\n\t\t\t\tjQuery(\"div#mmDeferVideoEncompass_Gujeh2yhPz0\").prepend(helpTag);\n\t\t\t\tsetTimeout(function(){jQuery(\"div#mmDeferVideoYTMessage_Gujeh2yhPz0\").css(\"display\", \"block\");}, 2000);\n\t\t\t  });\n\t\t\t  \n\t\t\t<\/script>\n\t\t\n<p><script>\nfunction SPs_Function() {\n  var x = document.getElementById(\"SPs\");\n  if (x.style.display === \"none\") {\n    x.style.display = \"block\";\n  } else {\n    x.style.display = \"none\";\n  }\n}\n<\/script><\/p>\n<div class=\"moc-toc hide-on-desktop hide-on-tablet\">\n<div><button onclick=\"SPs_Function()\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2024\/12\/toc2.svg\" width=\"16\" height=\"16\" alt=\"show or hide table of contents\"><\/button><\/p>\n<p>On this page<\/p>\n<\/div>\n<nav id=\"SPs\" style=\"display:none;\">\n<ul>\n<li class=\"toc-h2\"><a href=\"#Different_Types_of_Triangles\" class=\"smooth-scroll\">Different Types of Triangles<\/a><\/li>\n<li class=\"toc-h2\"><a href=\"#Frequently_Asked_Questions\" class=\"smooth-scroll\">Frequently Asked Questions<\/a><\/li>\n<li class=\"toc-h2\"><a href=\"#Types_of_Triangles_by_Shapes_and_Names_PDF\" class=\"smooth-scroll\">Types of Triangles by Shapes and Names PDF<\/a><\/li>\n<li class=\"toc-h2\"><a href=\"#Types_of_Triangles_Practice_Questions\" class=\"smooth-scroll\">Types of Triangles Practice Questions<\/a><\/li>\n<\/ul>\n<\/nav>\n<\/div>\n<div class=\"accordion\"><input id=\"transcript\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"transcript\">Transcript<\/label><input id=\"FAQs\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"FAQs\">FAQs<\/label><input id=\"factsheet\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"factsheet\">Fact Sheet<\/label><input id=\"PQs\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQs\">Practice<\/label>\n<div class=\"spoiler\" id=\"transcript-spoiler\">\n<p>Hi, and welcome to this review of different types of triangles! Before we begin, here\u2019s a review of the basics.<\/p>\n<p>A triangle has three straight sides that connect. The length of the sides can vary but the length of the largest side can\u2019t be equal or greater to the sum of the other two sides. In addition, a triangle has three interior angles, and the sum of those three angles is always 180 degrees. This is true for all triangles, including the six types we&#8217;re looking at today.<\/p>\n<h2><span id=\"Different_Types_of_Triangles\" class=\"m-toc-anchor\"><\/span>Different Types of Triangles<\/h2>\n<p>We\u2019re going to break our six types of triangles into two groups of three.<\/p>\n<p>Let\u2019s start with the three types of triangles that are categorized by the measure of their largest angle. These are the acute, right, and obtuse triangles.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/three-triangles-01.svg\" alt=\"\" width=\"500.4\" height=\"131.4\" class=\"aligncenter size-full wp-image-197633\"  role=\"img\" \/><\/p>\n<p>But how do you know which is which? Take a look at the largest angle of each triangle and note whether or not the angle is more than, less than, or equal to 90 degrees. <\/p>\n<h3><span id=\"Acute_Triangle\" class=\"m-toc-anchor\"><\/span>Acute Triangle<\/h3>\n<p>\nWe can see that the largest angle in the triangle on the left is 70 degrees. 70 is less than 90, so this is an acute triangle. Just remember that acute angles are less than 90 degrees. This one is easy to remember, since \u201ccute\u201d things are often small, like puppies and kittens.<\/p>\n<h3><span id=\"Right_Triangle\" class=\"m-toc-anchor\"><\/span>Right Triangle<\/h3>\n<p>\nWe can see that in the middle triangle the largest angle is exactly 90 degrees. You might remember that a 90-degree angle is a right angle, so this triangle is a right triangle.<\/p>\n<h3><span id=\"Obtuse_Triangle\" class=\"m-toc-anchor\"><\/span>Obtuse Triangle<\/h3>\n<p>\nFinally, in the triangle on the right, the largest angle is 117 degrees. Because this is more than 90 degrees, this is an obtuse angle, so we call this triangle an obtuse triangle. <\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/three-triangles-labeled-01.svg\" alt=\"\" width=\"500.4\" height=\"156.6\" class=\"aligncenter size-full wp-image-197645\"  role=\"img\" \/><\/p>\n<p>That\u2019s all there is to it for these three types! We just find the largest angle and the name of the triangle will correspond to the name of that angle. <\/p>\n<p>Our second set of triangles is categorized by how many of the sides have the same length. Here are three triangles with the lengths of the sides included:<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/three-triangles-with-side-lengths-01.svg\" alt=\"\" width=\"530.625\" height=\"150\" class=\"aligncenter size-full wp-image-197657\"  role=\"img\" \/><\/p>\n<h3><span id=\"Equilateral_Triangle\" class=\"m-toc-anchor\"><\/span>Equilateral Triangle<\/h3>\n<p>\nIn the triangle on the left, we can see that all three sides are the same length and measure 9 centimeters. A triangle like this one where all the sides are the same is called an equilateral triangle. It\u2019s not too tough of a name to remember since the beginning of equilateral sounds like the word equal, and the word lateral means \u201cside.\u201d <\/p>\n<h3><span id=\"Isosceles_Triangle\" class=\"m-toc-anchor\"><\/span>Isosceles Triangle<\/h3>\n<p>\nIn the middle triangle, we can see that two of the sides are the same length and measure 8 cm while the third is 9 cm. When two of the sides of a triangle are the same it\u2019s called an isosceles triangle. It\u2019s a hard one to spell, but an easy one to recognize! <\/p>\n<h3><span id=\"Scalene_Triangle\" class=\"m-toc-anchor\"><\/span>Scalene Triangle<\/h3>\n<p>\nIn our last triangle, none of the sides have the same length, so this is called a scalene triangle.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/labeled-triangles-with-measurements-01.svg\" alt=\"\" width=\"530.625\" height=\"150\" class=\"aligncenter size-full wp-image-197687\"  role=\"img\" \/><\/p>\n<p>While you often see these three types of triangles identified by the lengths of their sides, they can also be categorized by their angles. It works exactly the same way: <\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/labeled-triangles-with-angles-01.svg\" alt=\"\" width=\"530.625\" height=\"138.75\" class=\"aligncenter size-full wp-image-197681\"  role=\"img\" \/><\/p>\n<p>When all the angles are the same 60 degrees, it\u2019s an <strong>equilateral triangle<\/strong>. Technically, it\u2019s called an equiangular triangle but they\u2019re exactly the same thing because all equilateral triangles are also equiangular triangles. When two of the angles are the same it\u2019s an isosceles triangle. And when none of the angles are the same it\u2019s a scalene triangle. <\/p>\n<p>So far, we\u2019ve covered six types of triangles, which is technically all of the types, but we\u2019re not done yet. If we wanted to be really specific when naming our triangles, we can combine names from each group; one from the first group and one from the second group. <\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/acute-scalene-01.svg\" alt=\"\" width=\"222.6\" height=\"168\" class=\"aligncenter size-full wp-image-198131\"  role=\"img\" \/><\/p>\n<p>For instance, the triangle above is an <strong>acute scalene triangle<\/strong>. Its largest angle is less than 90 degrees, so it\u2019s acute, and none of its angles are the same, so it is scalene. <\/p>\n<p>Before we go, how about you give it a try. Identify these two triangles by choosing either acute, right, or obtuse and then choosing equilateral, isosceles, or scalene. <\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/Identifying-two-triangles-01.svg\" alt=\"\" width=\"465.92\" height=\"327.6\" class=\"aligncenter size-full wp-image-198149\"  role=\"img\" \/><\/p>\n<p>Think you got it? The triangle on the left is an <strong>obtuse scalene<\/strong> triangle, while the one on the right is a <strong>right isosceles<\/strong> triangle.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/09\/Identifying-two-triangles-solved-01.svg\" alt=\"\" width=\"471.77\" height=\"234.65\" class=\"aligncenter size-full wp-image-198146\"  role=\"img\" \/><\/p>\n<p>I hope this review was helpful! Thanks for watching, and happy studying!<\/p>\n<div style=\"text-align: center;\"><a class=\"ylist\" href=\"https:\/\/www.mometrix.com\/academy\/general-rules-of-triangles\/\">General Rules of Triangles<\/a> | <a class=\"ylist\" href=\"https:\/\/www.mometrix.com\/academy\/area-and-perimeter-of-a-triangle\/\">Area &#038; Perimeter of a Triangle<\/a><\/div>\n<p>&nbsp;<\/p>\n<ul class=\"citelist\">\n<li><a href=\"https:\/\/www.mathopenref.com\/tocs\/triangletoc.html\"target=\"_blank\">\u201cTriangles &#8211; Math Open Reference.\u201d n.d. Www.mathopenref.com.<\/a><\/li>\n<\/ul>\n<\/div>\n<div class=\"spoiler\" id=\"FAQs-spoiler\">\n<h2 style=\"text-align:center\"><span id=\"Frequently_Asked_Questions\" class=\"m-toc-anchor\"><\/span>Frequently Asked Questions<\/h2>\n<div class=\"faq-list\">\n<div class=\"qa_wrap\">\n<div class=\"q_item text_bold\">\n<h4 class=\"letter\">Q<\/h4>\n<p style=\"line-height: unset;\">What are the six types of triangles?<\/p>\n<\/p><\/div>\n<div class=\"a_item\">\n<h4 class=\"letter text_bold\">A<\/h4>\n<p>The six types of triangles are: isosceles, equilateral, scalene, obtuse, acute, and right.<\/p>\n<p>An <strong>isosceles triangle<\/strong> is a triangle with two congruent sides and one unique side and angle.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/Isosceles-triangle-e1770214964334.png\" alt=\"Isosceles triangle\" width=\"154.02\" height=\"197.54\" class=\"aligncenter size-full wp-image-69710\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/Isosceles-triangle-e1770214964334.png 453w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/Isosceles-triangle-e1770214964334-234x300.png 234w\" sizes=\"(max-width: 453px) 100vw, 453px\" \/><\/p>\n<p>An <strong>equilateral triangle<\/strong> is a triangle with three congruent sides and three congruent angles.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-69713 aligncenter\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/equilateral-triangle.png\" alt=\"equilateral triangle\" width=\"179\" height=\"174\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/equilateral-triangle.png 555w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/equilateral-triangle-300x291.png 300w\" sizes=\"auto, (max-width: 179px) 100vw, 179px\" \/><\/p>\n<p>A <strong>scalene triangle<\/strong> is a triangle with no congruent sides and no congruent angles.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-69716 aligncenter\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/scalene-triangle.png\" alt=\"scalene triangle\" width=\"156\" height=\"194\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/scalene-triangle.png 733w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/scalene-triangle-241x300.png 241w\" sizes=\"auto, (max-width: 156px) 100vw, 156px\" \/><\/p>\n<p>An <strong>obtuse triangle<\/strong> is a triangle that has an obtuse angle.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-69719 aligncenter\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/obtuse-triangle-with-108-degree-angle.png\" alt=\"obtuse triangle with 108 degree angle\" width=\"226\" height=\"99\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/obtuse-triangle-with-108-degree-angle.png 836w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/obtuse-triangle-with-108-degree-angle-300x131.png 300w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/obtuse-triangle-with-108-degree-angle-768x336.png 768w\" sizes=\"auto, (max-width: 226px) 100vw, 226px\" \/><\/p>\n<p>An <strong>acute triangle<\/strong> is a triangle that has three acute angles.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-69722 aligncenter\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/acute-triangle-with-each-angle-of-60-degrees.png\" alt=\"acute triangle with each angle of 60 degrees\" width=\"161\" height=\"154\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/acute-triangle-with-each-angle-of-60-degrees.png 526w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/acute-triangle-with-each-angle-of-60-degrees-300x287.png 300w\" sizes=\"auto, (max-width: 161px) 100vw, 161px\" \/><\/p>\n<p>A <strong>right triangle<\/strong> is a triangle that has one right angle.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-69725 aligncenter\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/right-triangle.png\" alt=\"right triangle\" width=\"150\" height=\"133\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/right-triangle.png 568w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/right-triangle-300x265.png 300w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"qa_wrap\">\n<div class=\"q_item text_bold\">\n<h4 class=\"letter\">Q<\/h4>\n<p style=\"line-height: unset;\">What are properties of a scalene triangle?<\/p>\n<\/p><\/div>\n<div class=\"a_item\">\n<h4 class=\"letter text_bold\">A<\/h4>\n<p>Scalene triangles are triangles that have three unique side lengths and three unique angle measures.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"qa_wrap\">\n<div class=\"q_item text_bold\">\n<h4 class=\"letter\">Q<\/h4>\n<p style=\"line-height: unset;\">What is scalene and right?<\/p>\n<\/p><\/div>\n<div class=\"a_item\">\n<h4 class=\"letter text_bold\">A<\/h4>\n<p>A scalene triangle is a triangle that has no equal sides or angles. A right triangle is a triangle that has one right (90\u00b0) angle. A triangle can be scalene and right if one of its unique angle measures is 90\u00b0.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2026\/02\/Scalene-Triangle-Example.svg\" alt=\"A right triangle with angles of 60\u00b0, 30\u00b0, and 90\u00b0, and side lengths of 2 in, 3.6 in, and 4 in.\" width=\"289.8\" height=\"164.22\" class=\"aligncenter size-full wp-image-286714\"  role=\"img\" \/><\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"qa_wrap\">\n<div class=\"q_item text_bold\">\n<h4 class=\"letter\">Q<\/h4>\n<p style=\"line-height: unset;\">How many sides are equal in an isosceles triangle?<\/p>\n<\/p><\/div>\n<div class=\"a_item\">\n<h4 class=\"letter text_bold\">A<\/h4>\n<p>An isosceles triangle has two equal sides and two equal angles.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"qa_wrap\">\n<div class=\"q_item text_bold\">\n<h4 class=\"letter\">Q<\/h4>\n<p style=\"line-height: unset;\">What is a true triangle?<\/p>\n<\/p><\/div>\n<div class=\"a_item\">\n<h4 class=\"letter text_bold\">A<\/h4>\n<p>A true triangle is a shape that has three sides and three angles. The lengths of two of the sides must add up to a number greater than the third side, and the three angles must add up to 180\u00b0.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"qa_wrap\">\n<div class=\"q_item text_bold\">\n<h4 class=\"letter\">Q<\/h4>\n<p style=\"line-height: unset;\">Which angles are equal in an isosceles triangle?<\/p>\n<\/p><\/div>\n<div class=\"a_item\">\n<h4 class=\"letter text_bold\">A<\/h4>\n<p>The two angles that are equal in an isosceles triangle are the two base angles. An isosceles triangle has two equal sides that meet at a point. The angle made by these two lines meeting is the unique angle. The angles formed by the bases of these lines and a third, unique side, are the two equal angles, called base angles.<\/p>\n<p><img decoding=\"async\" class=\"wp-image-69731 aligncenter\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/isosceles-triangle-with-base-angles.png\" alt=\"isosceles triangle with base angles\" width=\"157.2\" height=\"176.4\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/isosceles-triangle-with-base-angles.png 556w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/isosceles-triangle-with-base-angles-267x300.png 267w\" sizes=\"(max-width: 556px) 100vw, 556px\" \/><\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div class=\"qa_wrap\">\n<div class=\"q_item text_bold\">\n<h4 class=\"letter\">Q<\/h4>\n<p style=\"line-height: unset;\">What are the characteristics of an equilateral triangle?<\/p>\n<\/p><\/div>\n<div class=\"a_item\">\n<h4 class=\"letter text_bold\">A<\/h4>\n<p>An equilateral triangle is a triangle that has three equal sides and three equal angles.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<\/div>\n<\/div>\n<div class=\"spoiler\" id=\"factsheet-spoiler\">\n<h2 style=\"text-align:center\"><span id=\"Types_of_Triangles_by_Shapes_and_Names_PDF\" class=\"m-toc-anchor\"><\/span>Types of Triangles by Shapes and Names PDF<\/h2>\n<div>\n\t\t\t\t\t<img width=\"1362\" height=\"1766\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2022\/02\/image_2022-02-17_125941.png\" class=\"attachment-full size-full\" alt=\"A diagram illustrating six types of triangles: acute, obtuse, right, isosceles, equilateral, and scalene, each with a brief description of their properties. A QR code and Mometrix logo are at the bottom.\" decoding=\"async\" loading=\"lazy\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2022\/02\/image_2022-02-17_125941.png 1362w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2022\/02\/image_2022-02-17_125941-231x300.png 231w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2022\/02\/image_2022-02-17_125941-790x1024.png 790w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2022\/02\/image_2022-02-17_125941-768x996.png 768w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2022\/02\/image_2022-02-17_125941-1185x1536.png 1185w\" sizes=\"auto, (max-width: 1362px) 100vw, 1362px\" \/><\/p>\n<div class=\"sub_categories\">\n\t\t\t\t\t\t<a href=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2022\/02\/Types-of-Triangles.pdf\"><span id=\"Your_Types_of_Triangles_PDF_Download\" class=\"m-toc-anchor\"><\/span>Your Types of Triangles PDF Download<\/a>\n\t\t\t\t\t<\/div>\n<\/p>\n<\/div>\n<\/div>\n<div class=\"spoiler\" id=\"PQs-spoiler\">\n<h2 style=\"text-align:center\"><span id=\"Types_of_Triangles_Practice_Questions\" class=\"m-toc-anchor\"><\/span>Types of Triangles Practice Questions<\/h2>\n\n\t\t\t\t<div class=\"PQ\">\n\t\t\t\t\t<strong>Question #1:<\/strong>\n\t\t\t\t\t<div style=\"margin-left:10px;\"><p>&nbsp;<br \/>\nWhat kind of triangle is this?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-63520\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2020\/12\/Triangle-with-side-lengths-7-13-and-21.png\" alt=\"Triangle with side lengths 7, 13, and 21\" width=\"277\" height=\"110\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2020\/12\/Triangle-with-side-lengths-7-13-and-21.png 1130w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2020\/12\/Triangle-with-side-lengths-7-13-and-21-300x119.png 300w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2020\/12\/Triangle-with-side-lengths-7-13-and-21-1024x407.png 1024w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2020\/12\/Triangle-with-side-lengths-7-13-and-21-768x305.png 768w\" sizes=\"auto, (max-width: 277px) 100vw, 277px\" \/><\/p>\n<\/div>\n\t\t\t\t\t<div class=\"PQ-Choices\"><div class=\"PQ\"  id=\"PQ-1-1\">Acute<\/div><div class=\"PQ\"  id=\"PQ-1-2\">Equilateral<\/div><div class=\"PQ\"  id=\"PQ-1-3\">Isosceles<\/div><div class=\"PQ correct_answer\"  id=\"PQ-1-4\">Scalene<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<input id=\"PQ-1\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-1\" style=\"width: 150px;\">Show Answer<\/label>\n\t\t\t\t\t<div class=\"answer\" id=\"PQ-1-spoiler\">\n\t\t\t\t\t\t<strong>Answer:<\/strong><div style=\"margin-left:10px;\"><p>The correct answer is scalene. A scalene triangle is a triangle with no equivalent sides.<\/p>\n<\/div>\n\t\t\t\t\t\t<input id=\"PQ-1-hide\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-1-hide\" style=\"width: 150px;\">Hide Answer<\/label>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"PQ\">\n\t\t\t\t\t<strong>Question #2:<\/strong>\n\t\t\t\t\t<div style=\"margin-left:10px;\"><p>&nbsp;<br \/>\nWhat kind of triangle is this?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2025\/10\/Perimeter-of-an-isosceles-triangle-example.svg\" alt=\"A triangle with a base of 8 cm and two equal sides each measuring 13 cm.\" width=\"234\" height=\"250\" class=\"aligncenter size-full wp-image-273952\"  role=\"img\" \/><\/p>\n<\/div>\n\t\t\t\t\t<div class=\"PQ-Choices\"><div class=\"PQ\"  id=\"PQ-2-1\">Obtuse isosceles<\/div><div class=\"PQ correct_answer\"  id=\"PQ-2-2\">Acute isosceles<\/div><div class=\"PQ\"  id=\"PQ-2-3\">Acute scalene<\/div><div class=\"PQ\"  id=\"PQ-2-4\">Obtuse scalene<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<input id=\"PQ-2\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-2\" style=\"width: 150px;\">Show Answer<\/label>\n\t\t\t\t\t<div class=\"answer\" id=\"PQ-2-spoiler\">\n\t\t\t\t\t\t<strong>Answer:<\/strong><div style=\"margin-left:10px;\"><p>The correct answer is acute isosceles. An isosceles triangle has two congruent sides (as shown by the two tick marks) and one unique side. It is acute because the unique angle (the one on top) is less than 90\u00b0.<\/p>\n<\/div>\n\t\t\t\t\t\t<input id=\"PQ-2-hide\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-2-hide\" style=\"width: 150px;\">Hide Answer<\/label>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"PQ\">\n\t\t\t\t\t<strong>Question #3:<\/strong>\n\t\t\t\t\t<div style=\"margin-left:10px;\"><p>&nbsp;<br \/>\nWhat kind of triangle is this?<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/equilateral-triangle.png\" alt=\"equilateral triangle\" width=\"222\" height=\"215.2\" class=\"aligncenter size-full wp-image-69713\" srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/equilateral-triangle.png 555w, https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2021\/02\/equilateral-triangle-300x291.png 300w\" sizes=\"(max-width: 555px) 100vw, 555px\" \/><\/p>\n<\/div>\n\t\t\t\t\t<div class=\"PQ-Choices\"><div class=\"PQ\"  id=\"PQ-3-1\">Acute<\/div><div class=\"PQ\"  id=\"PQ-3-2\">Obtuse<\/div><div class=\"PQ correct_answer\"  id=\"PQ-3-3\">Equilateral<\/div><div class=\"PQ\"  id=\"PQ-3-4\">Scalene<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<input id=\"PQ-3\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-3\" style=\"width: 150px;\">Show Answer<\/label>\n\t\t\t\t\t<div class=\"answer\" id=\"PQ-3-spoiler\">\n\t\t\t\t\t\t<strong>Answer:<\/strong><div style=\"margin-left:10px;\"><p>The correct answer is equilateral. An equilateral triangle is a triangle with three congruent sides and three congruent angles.<\/p>\n<\/div>\n\t\t\t\t\t\t<input id=\"PQ-3-hide\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-3-hide\" style=\"width: 150px;\">Hide Answer<\/label>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"PQ\">\n\t\t\t\t\t<strong>Question #4:<\/strong>\n\t\t\t\t\t<div style=\"margin-left:10px;\"><p>&nbsp;<br \/>\nWhat kind of triangle is this?<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2026\/02\/Obtuse-Isosceles-Triangle-example.svg\" alt=\"A triangle with angles labeled 128 degrees at the top and 26 degrees at each of the two base corners.\" width=\"327.56\" height=\"86.64\" class=\"aligncenter size-full wp-image-286717\"  role=\"img\" \/><\/p>\n<\/div>\n\t\t\t\t\t<div class=\"PQ-Choices\"><div class=\"PQ\"  id=\"PQ-4-1\">Acute isosceles<\/div><div class=\"PQ\"  id=\"PQ-4-2\">Acute scalene<\/div><div class=\"PQ correct_answer\"  id=\"PQ-4-3\">Obtuse isosceles<\/div><div class=\"PQ\"  id=\"PQ-4-4\">Obtuse scalene<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<input id=\"PQ-4\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-4\" style=\"width: 150px;\">Show Answer<\/label>\n\t\t\t\t\t<div class=\"answer\" id=\"PQ-4-spoiler\">\n\t\t\t\t\t\t<strong>Answer:<\/strong><div style=\"margin-left:10px;\"><p>The correct answer is obtuse isosceles. An isosceles triangle is one with two congruent sides and two congruent angles and one unique side and angle. This triangle has two congruent angles on the bottom. It is obtuse because the unique angle is greater than 90\u00b0.<\/p>\n<\/div>\n\t\t\t\t\t\t<input id=\"PQ-4-hide\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-4-hide\" style=\"width: 150px;\">Hide Answer<\/label>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"PQ\">\n\t\t\t\t\t<strong>Question #5:<\/strong>\n\t\t\t\t\t<div style=\"margin-left:10px;\"><p>&nbsp;<br \/>\nWhat kind of triangle is this?<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2026\/02\/Obtuse-Scalene-Triangle-example.svg\" alt=\"A triangle with angles labeled 29\u00b0, 37\u00b0, and 114\u00b0.\" width=\"309.12\" height=\"103.74\" class=\"aligncenter size-full wp-image-286720\"  role=\"img\" \/><\/p>\n<\/div>\n\t\t\t\t\t<div class=\"PQ-Choices\"><div class=\"PQ\"  id=\"PQ-5-1\">Acute scalene<\/div><div class=\"PQ correct_answer\"  id=\"PQ-5-2\">Obtuse scalene<\/div><div class=\"PQ\"  id=\"PQ-5-3\">Acute isosceles<\/div><div class=\"PQ\"  id=\"PQ-5-4\">Obtuse isosceles<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<input id=\"PQ-5\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-5\" style=\"width: 150px;\">Show Answer<\/label>\n\t\t\t\t\t<div class=\"answer\" id=\"PQ-5-spoiler\">\n\t\t\t\t\t\t<strong>Answer:<\/strong><div style=\"margin-left:10px;\"><p>The correct answer is obtuse scalene. A scalene triangle is one with three unique side lengths and angle measures. It is obtuse because the largest angle is greater than 90\u00b0.<\/p>\n<\/div>\n\t\t\t\t\t\t<input id=\"PQ-5-hide\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"PQ-5-hide\" style=\"width: 150px;\">Hide Answer<\/label>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div><\/div>\n<\/div>\n\n<div class=\"home-buttons\">\n<p><a href=\"https:\/\/www.mometrix.com\/academy\/geometry\/\">Return to Geometry Videos<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Return to Geometry Videos<\/p>\n","protected":false},"author":1,"featured_media":91723,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":{"0":"post-21715","1":"page","2":"type-page","3":"status-publish","4":"has-post-thumbnail","6":"page_category-math-advertising-group","7":"page_category-triangle-videos","8":"page_type-video","9":"content_type-fact-sheet","10":"content_type-practice-questions","11":"subject_matter-math"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages\/21715","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/comments?post=21715"}],"version-history":[{"count":6,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages\/21715\/revisions"}],"predecessor-version":[{"id":197648,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages\/21715\/revisions\/197648"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/media\/91723"}],"wp:attachment":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/media?parent=21715"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}