SOLUTION
Part C.
A rectangular prism is a cubiod with a cross section along the length. in a rectangular prism, the opposite faces have equal dimemsion.
Consider the image below.
Hence
The surface of the water will have the same dimemsion as the base of the rectangular prism.
Therefore
The dimension of the surface of the water will be
length 3ft and width=1.5ft (3ft by 1.5ft)