Cecilia built a model pyramid out of foam. Her model is 20 inches high, with a rectangular base that is 8 inches long and 12 inches wide. What is the volume of her model in cubic inches?
The volume of a rectangular pyramid is given by the formula (1/3) * base area * height. The base area of Cecilia's pyramid is 8 inches * 12 inches = <<8*12=96>>96 square inches. Substituting the given values into the formula, we find that the volume is (1/3) * 96 square inches * 20 inches = <<(1/3)*96*20=640>>640 cubic inches. Answer: \boxed{640}.
