The objectives of this lesson are . . .
- to derive the formulas for surface area of pyramids and cones
- use the concept of netting to help visualize calculations
- practice finding areas of pyramids and cones
- provide additional non-standard practice in problem solving using pyramids and cones
The lesson consists of 5 separate slides shows, two of which provide details about the formulas for the surface area of a cone and a pyramid. The other slide shows provide practice problems and solutions.
Photographs used in this packet were obtained at morguefile.com. Morguefile grants permission to use its images.
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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
Now we will turn our attention to cones.
