Answer: 7ft
Step-by-step explanation:
The shape is a trapezium
Area of Trapezium= (1/2)(a+b)(h)
Area of Trapezium= 40sqft
a= x
b= 9ft
h= 5ft
40= (1/2)(x+9)(5)
40= (5(x+9)/2)
Cross multiply
80= 5(x+9)
80= 5x + 45
5x= 80-45
5x= 35
Divide both sides by 5
x= 7
