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Question
The curved surface area of a right circular cone of height 15 cm and base diameter 16 cm is
Options
60π cm2
68π cm2
120π cm2
136π cm2
Solution
136 cm2
Explanation;
Hint:
Here, h = 15 cm, r = 8 cm
l = `sqrt("h"^2 + "r"^2)`
= `sqrt(15^2 + 8^2)`
= `sqrt(225 + 64)`
= `sqrt(289)`
= 17
C.S.A of a cone
= πrl sq.units.
= π × 8 × 17
= 136π cm2
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