# Area and Perimeter by Definition

# 2 Ways to Measure 2-D

When it comes to 2-dimensional shapes, there are two concepts you need to understand very, very well for your math test: area and perimeter.

## LEARN IT

Consider a two-dimensional shape- like a rectangle, triangle, or trapezoid; there are two ways to think about "measuring" them. You can measure the length of the line around the outside of the shape, that's the perimeter, or you can measure the space to cover a shape, that's the area. When the two dimensional shape you're looking at is a rectangle, both measurements are quite simple. To find the perimeter, add up all the sides. To find the area, multiply the two dimensions of a rectangle, the length and width.

### Watch the Virtual GED Class video below for a complete explanation and tons of worked example problems.

## PRACTICE IT

One step area and perimeter application problems. See example #1-5 below.

Multi-step area and perimeter application problems. See examples #6&7 and extensions #1-5 below.

Graphs and charts and working backwards add GED style challenge. See extensions #6-9 below.

## WORKED EXAMPLES

Visual Explanation

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

Extension 1

Extension 2

Extension 3

Extension 4

Extension 5

Extension 6

Extension 7

Extension 8

Extension 9

Extension 10