A trapezoid is a quadrilateral with exactly one pair of parallel sides.
Formula for area: [tex]A = \frac{1}{2}(^{b}1 + ^{b}2)(h)[/tex]
In this formula, the bases are the parallel sides.
Now plug the information into the formula.
[tex]A = \frac{1}{2} (3 + 5)(9)[/tex].
Follow your order of operations, simplify inside the parentheses first.
[tex]A = \frac{1}{2}(8)(9)[/tex].
(1/2)(8) is 4 so we have (4)(9) which is 36.
So the area of the trapezoid is 36.