Surface Area of Pyramids

1
Surface Area of Pyramids Cones
2
Vocabulary

• Slant Height
• of a pyramid or cone is measured along its
  lateral surface.
• Regular Pyramid
• is a regular polygon, the lateral faces are all
  congruent.
• Right Cone
• is a line perpendicular to the base through the
  tip of the cone it passes through the center of
  the base.

3
Formulas

• Pyramid- SB1/2Pl or SBF
• Cone- SBL

4
Pyramid Example

• 2in
• 
  SB1/2Pl
• 
  (1.5x1.5)1/2(6)(2)
• 
  8.25in2
• 1.5

5
Cone Example

• 
  
• 2
  m
• 5 m
• Spi r2pi r l
• (2)2pi(2)(5)
• 14 pi
  14pi44.0m2

6
Story problems

• A cone has a diameter 10in and slant height 8in.
  Tell whether doubling both dimensions would
  double the surface area.
• Answer- NO
• The cone shaped Wigwams Village Motel in Cave
  City, Kentucky are about 20ft high and have a
  diameter if 20ft. Estimate the lateral surface
  area of a wigwam.
• Answer- 702.5ft2

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Problem
8 m
5m
8
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