Question

Calculate the surface area of cone whose curved surface area is $100{cm}^2$ and its radius $200$ cm.

• A. $125700cm$
• B. $125700{mm}^2$
• C. $125700m^2$
• D. $125700{cm}^2$

Answer 1

The correct option is D $125700{cm}^2$

Given, radius $r=200cm$ and curved surface area of the cone $=100c{m}^2$.

We know, surface area of a cone $=$ Curved surface area of a cone $+$ Area of circle.
$=\pi rs+\pi r^2$
$=100+3.14\times 200\times 200$
$=100+125600$
$=125700{cm}^2$.

Therefore, option $D$ is correct.