The longer diagonal of a right trapezoid is 13cm. the longer base is 12 cm. find the area of the trapezoid if the shorter base is 8cm.

A=1/2(b1+b2)h - area of trapezoid
to find the height we need to look at the right triangle inside the trapezoid
in the right triangle longest diagonal is a hypotenuse, so we need to us Pythagorean theorem