Warm up: Finding the Area of a Lateral Face

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Warm up Finding the Areaof a Lateral Face

• Architecture. The lateral faces of the Pyramid
  Arena in Memphis, Tennessee, are covered with
  steal panels. Use the diagram of the arena to
  find the area of each lateral face of this
  regular pyramid.

mynameismr.info/.../Surface20Area20of20Pyramids
2020Cones.ppt
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Pyramid Arena
mynameismr.info/.../Surface20Area20of20Pyramids
2020Cones.ppt
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mynameismr.info/.../Surface20Area20of20Pyramids
2020Cones.ppt
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Surface Area of a Cone

• Unit 5, Lesson 5
• Mrs. King

With slides from www.cohs.com/.../229_9.320Surfac
e20Area20of20Pyramids20and20Cones20C...
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Pyramids and Cones
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• A cone has a circular base and a vertex that is
  not in the same plane as a base.
• In a right cone, the height meets the base at its
  center.
• The height of a cone is the perpendicular
  distance between the vertex and the base.
• The slant height of a cone is the distance
  between the vertex and a point on the base edge.

The vertex is directly above the center of the
circle.
Height
Lateral Surface
Slant Height
r
Base
r
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Surface Area of a Cone

• Surface Area area of base area of sector
• area of base p(radius of base)(slant height)

r
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Lateral Area of a Cone

• Since Lateral Area Surface Area area of the
  base

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Example 1

• Find the surface area of the cone to the nearest
  whole number.
• a. r 4 slant height 6

4 in.
6 in.
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Example 2

• Find the surface area of the cone to the nearest
  whole number.
• b.
• First, find the slant height. Next, r 12,

5 ft.
12 ft.
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On your own 1

• Calculate the surface area of

• S ??(7)2 ?(7)(11.40)
• S 49? 79.80?
• S 128.8?

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On your own 2

• Calculate the lateral area of

• L.A. ?(5)(13)
• L.A. 65?