Question

The curved surface area and the total surface area of a hemisphere of radius 7 cm will be

• A. $308{cm}^2$ and $462{cm}^2$ respectively
• B. $318{cm}^2$ and $480{cm}^2$ respectively
• C. $310{cm}^2$ and $452{cm}^2$ respectively
• D. $328{cm}^2$ and $562{cm}^2$ respectively

Answer 1

The correct option is A

$308{cm}^2$ and $462{cm}^2$ respectively

Given, r = 7 cm

The curved surface area $=2\pi r^2$
$=2\times \frac{22}{7}\times 7^2$
$=308{cm}^2$

The total surface area of the hemisphere $=3\pi r^2$
$=3\times \frac{22}{7}\times 7^2$
$=462{cm}^2$