How do you find the area of a trapezoid?

In this lesson you will learn how to find the area of a trapezoid by composing a

parallelogram.

Let’s ReviewLet’s Review

You find the area of a rectangle by multiplying length times width.

length

widt

h

Let’s ReviewLet’s Review

You find the area of a parallelogram by multiplying the base by height.

base

heig

ht

Let’s ReviewA Common MistakeWhen decomposing a trapezoid, it is often forgotten to find half the area of the shape

you’ve created.

Let’s ReviewCore LessonLet’s find the area of a trapezoid.

21 units

5 un

its

21x 5

105 units¤ 52.5 units ¤ 2

Let’s ReviewCore Lesson

16 units

3 un

its

16x 3

48 units¤ 24 units ¤

Let’s find the area of an isosceles trapezoid.

2

In this lesson you have learned how to find the area of

trapezoids by composing a parallelogram.

Let’s ReviewGuided PracticeFind the area of the trapezoid.

Let’s ReviewExtension Activities

Draw a trapezoid on a piece of grid paper. Then, draw a congruent trapezoid. Connect the two trapezoids to form a parallelogram. Find the area of the parallelogram. Using the area of the parallelogram, find the area of each trapezoid.

Let’s ReviewExtension Activities

Using pattern blocks, put together shapes to create a trapezoid. Trace the trapezoid onto grid paper and then find the area using the strategies you’ve watched in this video.

Let’s ReviewQuick Quiz

1. Find the area. 2. Find the area.