There are three types of angles. An angle was formed when ever two lines meet together, (right here we have an angle, we have an angle right here, and we have an angle right here) so the three types of angles are acute, right, and obtuse.
Right here we have a right angle, and the angle measure for a right angle is exactly 90 degrees. A square is made up of four right angles. This line right here is perfectly vertical; this line right here is perfectly horizontal.
They’re (what we call) perpendicular to each other. Now if the angle measure is less than 90 degrees we call it acute, so this is (acute angle or) an acute angle. A good way to remember this is think about A Cute Little Angle (like a cute little angle).
Think about it being small, because a lot of times people think that animals that are really small are cute, so this angle right here is small, so we call it a ‘cute’ angle. It may sound a little bit silly, but it’s a good way to remember it.
Then we have this right here, which is an obtuse angle. An obtuse angle has an angle measured greater than 90 degrees. You can just look at this and realize that this angle measure is bigger than this one. Basically, the measure of an angle is how close the two lines are together.
Notice these two lines are really close to each other, These lines are a little farther apart, and then these lines are really far apart. Notice right here that ob- in obtuse is also like ob- in obese, which means overweight, so you can think about obtuse meaning big or very large.
That’s another little trick to remember it. Again, the three types of angles are right, acute, and obtuse. For all angles that measure less than 90 degrees, we call it an acute angle. For all angles that measure greater than 90 degrees, we call it an obtuse angle. Then for those angles that have a measure of exactly 90 degrees, we call it a right angle.