20. Note that the given figure is a parallelogram which means it is a quadrilateral with two pairs of parallel and equal sides:The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure.
(AC)2 = (AD)2 + (CD)2
(5in)2= (3in)2+ (CD)2
25 = 9 + (CD)2
25 - 9= (CD)2
16 = (CD)2
Taking square root of both sides, we have:
√16 = (√CD)2
4 = CD
h = 4 in
(Answer Without Area)
Finding area:-
Hint: you can use the above