Question

if total surface area of a solid hemisphere is 462 metre square find its volume

Answer 1

Finding  Radius of Hemisphere

We know that ,

Total Surface area of hemisphere = $3\pi r^2$

According to the Question :

$3\pi r^2 = 462 m^2$

Putting the values :

$3 * \frac{22}{7} * r^2 = 462$

➾ $\frac{66}{7} r^2 = 462$

➾ $462 * \frac{7}{66}$ = $r^2$

➾ 49 = $r^2$

➾ r = $\sqrt{49}$

➾ r = 7

Finding Volume of Hemisphere

Volume of hemisphere = $\frac{2}{3} \pi r^3$

➾ $\frac{2}{3} * \frac{22}{7} * 7 *7 *7$

➾ $718.6 \ cm^3$

# Be Concentrate

Answer 2

Total Surface area of hemisphere = 3 pie r^2

= 3× 22/7 r^2 = 462

r^2 = 462 × 7/ 22× 3

= 154 × 7/22

=7× 7= 49

r= 7 as -7 needs to be neglected

So volume = 2/3 pie r^3

= 2/3 × 22/7× 7× 7× 7

= 2/3× 22× 49

= 2156/3

= 718.66 m^3