# An Intro to Parallelograms

Welcome to this video lesson on common quadrilaterals.

Today, we will go over parallelograms, rectangles, and squares.

**a) parallelogram** = A parallelogram is a quadrilateral where all opposite sides are parallel and of equal length, and all opposite angles are equal.

To find the area of a parallelogram, multiply the length of of the sides, and multiply it by the height. In this case: x times h = area.

**b) rectangle** = A rectangle is a quadrilateral where all angles are equal to 90º, and all opposite sides are of equal length. The area of a rectangle is very easy to find, just like a parallelogram, height times width, in this case, x times y.

**c) square** = A square is a quadrilateral where all side lengths and angle measures are equal. Since all sides are equal, finding the area is simply a matter of multiplying any side by itself.

I hope that helps. Thanks for watching this video lesson, and until next time, happy studying.

## Practice Questions

**Question #1:**

Which of the following is not part of the definition of a parallelogram?

It is a quadrilateral

All angles are right angles

Opposite sides are parallel and of equal length

All opposite angles are equal

**Answer:**

The correct answer is all angles are right angles. The definition of a parallelogram is, a quadrilateral where all opposite sides are parallel and of equal length, and all opposite angles are equal.

**Question #2:**

What is the area of this parallelogram?

102 cm^{2}

212 cm^{2}

119 cm^{2}

204 cm^{2}

**Answer:**

The correct answer is 204 cm^{2}. The formula of a parallelogram is:

\(A=bh\)

The base (*b*) is 17 cm and the height (*h*) is 12 cm.

\(A=(170)(12)=204\text{ cm}^2\)

The area of this parallelogram is 204 cm^{2}.

**Question #3:**

“A quadrilateral where all side lengths and angle measures are equal” is the definition of what shape?

Parallelogram

Rectangle

Square

Trapezoid

**Answer:**

The correct answer is a square. This is the exact definition of a square. It has all equal sides and all equal angles.

**Question #4:**

What is the area of a square with a side length of 4 in?

24 in^{2}

16 in^{2}

8 in^{2}

32 in^{2}

**Answer:**

The correct answer is 16 in^{2}. The formula for area of a square is:

\(A=s^2\)

The length of the side (*s*) is 4 in.

\(A=(4)^2=16\text{ in}^2\)

The area of this square is 16 square inches.

**Question #5:**

What is the area of this rectangle?

77 ft^{2}

60 ft^{2}

36 ft^{2}

42 ft^{2}

**Answer:**

The correct answer is 77 ft^{2}. The formula for area of a rectangle is:

\(A=lw\)

The length (*l*) is 17 ft and the width (*w*) is 7 ft.

\(A=(11)(7)=77\text{ ft}^2\)

The area of this rectangle is 77 square inches.