Answer
See below.
Work Step by Step
$A=0.5h(a+b)\\a+b=\frac{2A}{h}\\a=\frac{2A}{h}$
This gives the base of the trapezoid with respect to the area, the height and the other base of it.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.