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Surface area of pyramids and cones

Author: Dan Bowler

The following terms may be new for this lesson:

pyramid - a polyhedron (many sided solid) in which the base is a polygon and the lateral faces (sides) are triangles with a common vertex

cone - has a circular base and a vertex that is not in the same plane as the base

Net - a two-dimensional representation of the faces of a solid (think of cutting it open and unfolding the sides)

Slant height - the altitude of any lateral face of a pyramid (or distance up the side of a right cone)

Source: Geometry; McDougal Littell (2004) by Larson, Boswell, and Stiff

This slide show will demonstrate the formula for the surface area of a pyramid.

Some practice problems and solutions for surface areas of pyramids.

Use trig to find the surface area of a pyramid with a pentagonal base. Up for a challenge??

Now we will turn our attention to cones.

This slide show will demonstrate the formula for the surface area of a cone.

Source: The image for the net of a cone was found at www.mathsteacher.com.au/. ../Image16380.gif

Engage in a battle of wits with the indomitable Mr. Bunny and practice finding surface areas of cones at the same time!