Question

The slant height of a frustum of a flower pot is 2 mm and the perimeters of its circular ends are 12 mm and 4 mm. Find the curved surface area of the flower pot.

• A. 13.7 $m{m}^2$
• B. 14.7 $m{m}^2$
• C. 15.7 $m{m}^2$
• D. 16.7 $m{m}^2$

Answer 1

The correct option is C 15.7 $m{m}^2$

Radius, $R=perimeter/2\pi =12/2\times 3.14\Rightarrow 1.9mm$

$r=perimeter/2\pi =4/2\times 3.14=0.6mm$

Curved surface area = $\pi (R+r)s$

$=3.14\times (1.9+0.6)\times 2$

$=3.14\times 2.5\times 2$

$=15.7m{m}^2$