Question

In isosceles trapezoid WKMN, WN=6, WK=9, and the perimeter of WKMN is 40. What is the length of KM?

A. 16
B. 12
C. 15
D. 25

Answer 1

Answer: The length of KM is 16.

In an isosceles trapezoid, the two non-parallel sides are congruent. Therefore, we have two options: either there are two 9's or two 6's in the trapezoid.

Let's try both options to find the length of the missing side:

40 - 9 - 6 - 6 = 19

OR

40 - 6 - 9 - 9 = 16

The only choice that is an option is 16.