Mensurationmedium · Past Paper

Find the total surface area of a cone whose radius is r/2 and slant height is 2l.

Aπr(l + r/4)
Bπr(l + r/2)
C2πrl
Dπrl + πr²

✓ Correct Answer: Aπr(l + r/4)

TSA = π(r/2)(2l + r/2) = π(r/2)(2l) + π(r/2)(r/2) = πrl + πr²/4 = πr(l + r/4).

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