Given: Radii (r ) = 14 cm, and (r ) = 6 cm, height (h) = 6 cm
Slant height of frustum (l)
i. Curved surface area of frustum
= πl (r1 + r2 )
= 3.14 × 10(14 + 6)
= 3.14 × 10 × 20 = 628 cm2
∴ The curved surface area of the frustum is 628 cm2 .
ii. Total surface area of frustum
= πl (r1 + r2 ) + πr12 + πr22
= 628 + 3.14 × (14)2 + 3.14 × (6)2
= 628 + 3.14 × 196 + 3.14 × 36
= 628 + 3.14(196 + 36)
= 628 + 3.14 × 232
= 628 + 728.48
= 1356.48 cm2
∴ The total surface area of the frustum is 1356.48 cm2.
iii. Volume of frustum
= 1/3 πth(r12 +r22 + r1 × r2 )
= 1/3 × 3.14 × 6(142 + 62 + 14 × 6)
= 3.14 × 2(196 + 36 + 84)
= 3.14 × 2 × 316
= 1984.48 cm3
∴ The volume of the frustum is 1984.48 cm3.