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Question
The perpendicular height of a cone is 12 cm and its slant height is 13 cm. Find the radius of the base of the cone.
Solution
Let the radius of the base of the cone be r cm.
Height of the cone, h = 12 cm
The slant height of the cone, l = 13 cm
Now,
`"r"^2 +"h"^2 = "l"^2`
⇒ `"r"^2 + (12)^2 = (13)^2`
⇒ `"r"^2 + 144 = 169`
⇒ `"r"^2 = 169 - 144 = 25`
⇒ `"r" = sqrt(25) = 5 "cm"`
Thus, the radius of the base of the cone is 5 cm.
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