Q8 of 107 Page 17

The radii of the circular bases of a frustum of a right circular cone are 12 cm and 3 cm and the height is 12 cm. Find the total surface area and the volume of the frustum.

Given: radius of bases of frustum = 12cm and 3cm and its height = 12cm


Let l be the slant height of the cone, then




⇒ l = 15cm


Total surface area of the frustum = π (r’ + r’’) × l + π r’2 + π r’’2


= π (12 + 3) + π × (122 + 32)


= 378 cm2


Volume =



= 756 π cm3


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