An isosceles trapezoid has perimeter of 42 inches. Each of the congruent nonparallel sides is 5 inches long, and the trapezoid is 3 inches tall. How long are the two parallel sides?

a. 12 inches and 20 inches

b. 10 inches and 22 inches

c. 10 inches and 16 inches

d. 16 inches and 16 inches

xeroxlion Feb 26, 2019

#1**0 **

Let the bottom base be the longer side

The non-parallel side and the height form a 3-4-5 right triangle

So....using symmetry....the bottom base is (4 + 4) = 8 units longer than the top base

So.....we have

x +( x + 8 )+ 5 + 5 = 42 simplify

2x + 18 = 42

2x = 24

x = 12 = the top base

x + 8 = 20 = the bottom base

So

a. 12 inches and 20 inches

CPhill Feb 26, 2019