The answer is 1,378 ft².
The area of the trapezoid is: A = (a+b)/2 * h, where a and b are bases and h is height.
We know that:
a = 100 ft
b = 112 ft
h = 13 ft
Calculate the area:
A = (a+b)/2 * h
A = (100 + 112)/2 * 13
A = 212/2 * 13
A = 106 * 13
A = 1,378 ft²