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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.
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.
