Trapezoid Perimeter Problem: Finding Missing Side CD When Total is 22 cm

Question

The perimeter of the trapezoid equals 22 cm.

AB = 7 cm

AC = 3 cm

BD = 3 cm

What is the length of side CD?

00:00 Find CD

00:03 The perimeter of a trapezoid equals the sum of its sides

00:10 We'll substitute appropriate values and solve for CD

00:31 Let's group terms

00:36 Let's isolate CD

00:46 And this is the solution to the question

Since we are given the perimeter of the trapezoid and not the length of CD, we can calculate:

$22=3+3+7+CD$

$22=CD+13$

$22-13=CD$

$9=CD$