What is the volume of this figure? a three-dimensional figure that is composed of two rectangular prisms. prism a has a width of 3 feet and a height of 8 feet. the width is unknown but can be determined by the width of prism b. prism b has a length of 2 feet, a width of 4 feet, and a height of 3 feet. 24 ft3 72 ft3 96 ft3 120 ft3