Q5 of 24 Page 227

If the volume of a right circular cone is 100 π cm3 and height is 12cm, then let us write by calculating, the slant height of the cone.

Let, base radius = r cm and slant height = l cm


Height = 12 cm


According to problem,


⇒ π × r2 ×h/3 = 100π



⇒ 4r2 = 100


⇒ r = 5


Base radius = 5 cm


∴ Slant height = √(h2 + r2) = √(122 + 52) = √(144 + 25) = 13 cm


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