## Area, Circumference, and Perimeter

Overview: In this lesson you will learn how to find the area of shapes, the circumference of shapes and the perimeter of shapes.

## How to Find the Area of Shapes

The area of a shape is the space inside of the shape. To find area you use the method length times width equals area or L•W=A

Definition: the inside space of a two-dimensional figure.

Definition: the inside space of a two-dimensional figure.

## What an area problem looks like

Area=Length•Width. In this problem the numbers are 53 inches and 21 inches. You should fill in the variable letters (L,W). So if your variable problem was; L•W=? you will put the 53 in the length spot and the 21 in the width spot. 53•21=113 inches.

## How to Find the circumference

The circumference is the distance around the circle

Definition:the outer boundary, especially of a circular area; perimeter:

Definition:the outer boundary, especially of a circular area; perimeter:

## How to Find the Perimeter of Shapes

The perimeter of a shape is the distance around the shape. To find area you use the method L+W+L+W=P.

Definition:the border or outer boundary of a two-dimensional figure.

Definition:the border or outer boundary of a two-dimensional figure.

## What a perimeter problem looks like

Perimeter=L+W+L+W

In this problem the numbers are: 50,73,50, and 73. You need to fill in the variable numbers. (L,W,L, and W). The variable problem was L+W+L+W=? You will put the 50's in the L spots and the 73's in the W spot. 50+73+50+73=246 inches.

In this problem the numbers are: 50,73,50, and 73. You need to fill in the variable numbers. (L,W,L, and W). The variable problem was L+W+L+W=? You will put the 50's in the L spots and the 73's in the W spot. 50+73+50+73=246 inches.

## What a circumference problem looks like

There are 2 different ways to find the circumference both shown on the left. The first is pi (3.14) times the diameter. The second one is 2 times pi (3.14) times radius.

Remember, the radius is half the size of the diameter and the diameter is 2 times larger than the radius.

Remember, the radius is half the size of the diameter and the diameter is 2 times larger than the radius.

## Diameter and Radius example problems

As you may have read above, there are 2 ways to find the circumference. pi times the diameter and 2 times pi time the radius.

Option number one example: 3.14•16 (diameter)

Option number two example:2•3.14•8 (radius)

Option number one example: 3.14•16 (diameter)

Option number two example:2•3.14•8 (radius)