Question

A cone is on a hemisphere ,whose combined diameter is 14cm .If height of the cone is 7 cm ,then find total surface area .

Answer 1

curved surface area of cone + curved surface

area of hemisphere =Total surface area.

$= > \pi \: rl + 2\pi {r}^{2}$

using slant height formula,

$= > l = \sqrt{ {h}^{2} + {r}^{2} }$

$= > l = \sqrt{ {7}^{2} + {7}^{2} }$

$= > l = \sqrt{49 + 49}$

$= > l = \sqrt{98}$

$= > l = 7 \sqrt{2}$

$= > \pi( \: 7 \times 7\sqrt{2} + 2 \times 7 \times 7)$

$= > \pi(49 \sqrt{2} + 98)$

$= > \frac{22}{7} (49 \times 1.41 + 98)$

$= > \frac{22}{7} (69.09 + 98)$

$= > \frac{22}{7} \times 169.09$

$= > 22 \times 24.155$

$= > 531.3 {cm}^{2}$

Hope this answer is helpful.