AREA REVIEW

Area: The number of square units (units²) it takes to cover the surface of a figure.

In the picture to the right, we would just count the squares.

The rectangle and square are easy.

The TRIANGLE presents a challenge

Area of a Triangle

(1) Made a copy of the triangle

(2) I flipped the copy

(3) Slid the copy over and now we have a parallelogram.

Area of a Triangle

Area of a Parallelogram

A = bh

(4) Count to find the base

(6 squares)

(5) Count to find the height

(5 squares)

(6) Find the area of the parallelogram. (30 squares)

ANSWER

The whole thing was 30 squares.

So...both triangles have to be 15 squares each.

Or the area of the triangle was the area of the parallelogram divided by 2.

30 ÷ 2 = 15

Area of a Triangle

EXAMPLE

​What is the area of this triangle?