Answer:
D
Step-by-step explanation:
The area (A) of a trapezoid is calculated as
A = 0.5h(a + b)
where h is the perpendicular height and a, b the parallel sides.
Given A = 120, then
0.5 × 8(a + b) = 120, that is
4(a + b) = 120 ( divide both sides by 4 )
a + b = 30 cm → D
