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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