Answer:
h = 17 units
Step-by-step explanation:
The area (A) of a trapezoid is calculated as
A = [tex]\frac{1}{2}[/tex] h (b₁ + b₂ )
where h is the height and b₁ , b₂ the parallel bases
Here A = 408, b₁ = 20, b₂ = 28 , then
[tex]\frac{1}{2}[/tex] h (20 + 28) = 408 ( multiply both sides by 2 to clear the fraction )
48h = 816 ( divide both sides by 48 )
h = 17
