The area of the triangular cross-section is 10 mm². Image caption, Next multiply the area of the cross-section by the length of the prism. 10 × 9 = 90. The volume of the prism is 90 mm³.

which is a triangular prism, holds the same volume as the old rectangular one. Applying the formula area of uniform cross-section × height to calculate the volume of various prisms, varying the ...