Surface Area of Pyramids, Cones and Spheres

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Surface Area of Pyramids, Cones and Spheres

• Math 8
• Measurement Unit

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SA of Pyramids

• If we were to look at a net of a square pyramid,
  it would look like the diagram below

How can I calculate the surface area?
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What about a triangular pyramid?

• How would I calculate the SA of this figure?

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Formulas to Calculate SA of Pyramids

• Formula to calculate the area of a triangular
  face
• A b X h 2
• To calculate a triangular base of a pyramid
• A b X h 2
• To calculate a square base of a pyramid
• A base X base

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Lets try one

• Calculate the SA of the following pyramid
  (include the base)

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Solution
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SA of Cones

• If we were to look at a net of a cone, it would
  look like the diagram below

How can I calculate the surface area?
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Formulas to Calculate SA of Cones

• Formula to calculate the area of the cone base
• A ??r2
• To calculate the lateral face of a cone
• A ??r?l (slant height)

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Lets try one

• Calculate the SA of the following cone (include
  the base)

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Solution
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SA of Spheres

• To calculate the SA of a sphere, the formula is
• A 4???r2

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Lets try one

• Calculate the SA of the following sphere

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Solution