Question

The circumference of lower and upper bases of the frustum cone is 250 and 120 cm. The slant height is 12 cm. Find the curved surface area.

• A. 2,120 $c{m}^2$
• B. 2,220 $c{m}^2$
• C. 2,320 $c{m}^2$
• D. 2,020 $c{m}^2$

Answer 1

The correct option is B 2,220 $c{m}^2$

Curved surface area of the frustum cone = $\frac{1}{2}(2\pi R+2\pi r)l$

$=\frac{1}{2}(250+120)\times 12$

$=370\times 6$

$=2,220$ $c{m}^2$