Volumes of Pyramids and Cones Find volumes of

Volumes of Pyramids and Cones – Find volumes of pyramids. – Find volumes of cones. Transamerica Building, San Francisco

VOLUMES OF PYRAMIDS The pyramid and the prism below share a base and have the same height. As you can see, the volume of the pyramid is less than the volume of the prism.

Key Concept Volume of a Pyramid If a pyramid has a volume of V cubic units, a height of h units, and a base with an area of B square units, then V = ⅓Bh h Area of base = B

Example 1 Volume of a Pyramid Travis is making a plaster model of a pyramid for a class presentation. The model is a square pyramid with a base edge of 12 inches and a height of 15 inches. Find the volume of plaster needed to make the model. 15 in. 12 in.

VOLUMES OF CONES If the areas of the bases of a cone and a cylinder are the same and if the heights are equal, then the volume of the cylinder is three times as much as the volume of the cone.

Key Concept Volume of a Cone If a right circular cone has a volume of V cubic units, a height of h units, and the base has a radius of r units, then V = ⅓Bh or V = ⅓ r 2 h h r

Example 2 Volume of a Cone Find the volume of the cone. 8 in.

Example 3 Volume of a Cone Find the volume of the cone. 10 in. 48°

Example 4 Volume of an Oblique Cone Find the volume of the oblique cone. 8. 6 in. 12 in.