Answer:
Length A: 5 ft
Width B: 4 ft
volume = 88 ft³
Explanation:
Length A: 8 - 3 = 5 ft
Width B: 8 - 4 = 4 ft
Volume
The easiest way to calculate the volume is to split the trough into two rectangular prisms. (imagine drawing a horizontal line from the internal corner of A and 4ft to the left 8ft side).
Volume of a rectangular prism = width x length x height
Volume of rectangular prism 1: B x 8 x 2 = 4 x 8 x 2 = 64 ft³
Volume of rectangular prism 2: 3 x 4 x 2 = 24 ft³
Total volume = 64 + 24 = 88 ft³