Question

Find the lengths of AD, EF, and BC in the trapezoid below.

Answer 1

We know that,

$EF=\dfrac{AD+BC}{2}$

which is

$x=\dfrac{x-5+2x-4}{2}$

Now solve for x,

$x=\dfrac{3x-9}{2}$

$2x=3x-9$

$x=9$

Since x is 9, the lengths are,

$AD=x-5=9-5=\boxed{4}$

$EF=x=\boxed{9}$

$BC=2x-4=18-4=\boxed{14}$

Hope this helps :)