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## Area of a Rectangle

#### Introduction

A rectangle is a four-sided polygon with two pairs of parallel sides. The angles between each of the sides are all right angles. A square is a type of rectangle that has four sides of the same length.

#### Terms

**Area**- A quantity that expresses the extent of a two-dimensional shape.

**Square**- A polygon with four equal straight sides and four right angles.

**Rectangle**- A polygon with four straight sides and four right angles, esp one with unequal adjacent sides.

**Right Angle**- An angle of 90 degrees.

## Lesson

Area of a Rectangle Formula

$ext{Area} imes a * b$, where a and b are the lengths of the sides of the rectangle.

If a rectangle has sides of length 4 and 5, for example, the area is

$ext{Area} = a imes b$

$ext{Area} = 4 imes 5$

$ext{Area} = 20$

## Examples

#### Area of a Rectangle

$\text{Area} = \text{Length} * \text{Width}$

$\text{Area} = 15 * 10$

$\text{Area} = 150$

#### Area of a Rectangle (w/ Decimals)

$\text{Area} = \text{Length} * \text{Width}$

$\text{Area} = 12.5 * 10.8$

$\text{Area} = 135$