Answer:
x = 13
Step-by-step explanation:
The area (A) of a trapezium is calculated as
A = [tex]\frac{1}{2}[/tex] h (b₁ + b₂ )
where h is the perpendicular height and b₁, b₂ the parallel bases
Here A = 55, h = 5. b₁ = x, b₂ = 9, then
[tex]\frac{1}{2}[/tex] × 5 × (x + 9) = 55
2.5(x + 9) = 55 ( divide both sides by 2.5 )
x + 9 = 22 ( subtract 9 from both sides )
x = 13
