A building is composed of a roof in the shape of a triangular prism. the volume of the roof is one half the volume of the rest of the building. how long is the building if the volume of the entire building and roof is 900 square meters and the base of the triangular prism that makes the roof has an area of 15 square meters?
a. 15 meters
b. 20 meters
c. 60 meters
d. 30 meters
