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Why do we use only the curved surface area (not the total surface area) for the sheet in a joker's cap?

Class 9Surface Area of a ConeMensuration
  • AThe cap is open at the bottom
  • BThe base is too small to matter
  • CThe cap has no slant height
  • DTotal surface area is used only for spheres

Step-by-Step Solution

A cap has no circular base — the head goes in there — so only the curved part needs material.
Answer: A) The cap is open at the bottom

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