Answer:
B. 60 ft²
Explanation:
The overall area of the parallelogram is the product of its base length (15 ft) and height (8 ft), so is ...
overall area = (15 ft)(8 ft) = 120 ft²
The area of the quadrilateral in the middle of the parallelogram is the area of two triangles, each with a base equal to 15 ft (the horizontal line in the diagram), and heights that total 8 ft. If we let x represent the height of one of those triangles, then the other has a height of (8-x) and the sum of their areas is ...
quadrilateral area = (1/2)(15 ft)(x) +(1/2)(15 ft)(8 ft -x)
= (1/2)(15 ft)(x + 8 ft - x) = (1/2)(15 ft)(8 ft) = 60 ft²
Then the shaded area is the difference between the parallelogram area and the quadrilateral area:
shaded area = parallelogram area - quadrilateral area
= (120 ft²) - (60 ft²)
= 60 ft²
The area of the shaded region is 60 ft².