The community center for watercrest has a large glass wall that looks out the lake find the area for the glass wall

The wall has a shape of trapezium, the area will therefore be given by:
A=1/2(a+b)*h
where a and b are the side length, h is height:
a=25, b=15, h=40
thus the area of the wall will be:
A=1/2(25+15)×40
A=1/2×40×40
A=800 ft²
Area=800 ft²