CK12 - Geometry

And, sincethe volumeof a squareprismis , we can write:

This can be writtenas the VolumePostulatefor pyramids.

Volumeof a PyramidGivena right pyramidwith a basethat has area and height

:

Example 5

Find the volumeof a pyramidwith a right trianglebasewith sidesthat measure

cm,

cm, and

cm. The heightof the pyramidis

cm.

First find the area of the base.The longestof the threesidesthat measure cm, cm, and cm must
be the hypotenuse,so the two shortersidesare the legs of the right triangle.

Now use the postulatefor the volumeof a pyramid.

Example 6

Find the altitudeof a pyramidwith a regularpentagonalbase.The figurehas an apothemof