Question

Find the volume curved surface area and the total surface area of a hemisphere of diameter 7cm

Answer 1

Radius of hemisphere = diameter/2
= 7/2 cm

Volume of hemisphere = 2/3 π r
= 2/3 * 22/7 * 7/2
= 22/3
= 7.33 cm³
Now,

Curved surface area = 2 π r²
= 2 * 22/7 * (7/2)²
= 2 * 22/7 * 49/4
= 77 cm²

Total surface area = 3 π r²
= 3 * 22/7 * (7/2)²
= 3 * 22/7 * 49/4
= 115.5 cm²

Answer 2

$\textbf{\underline{\underline{According\:to\:the\:Question}}}$

★R of hemisphere = 7cm

★Using Formula :-

★Volume of hemisphere :-

$\tt{\rightarrow(\dfrac{2}{3}\pi r^3}$

$\tt{\rightarrow\dfrac{2}{3}\times\dfrac{22}{7}\times\dfrac{7}{2}\times\dfrac{7}{2}\times\dfrac{7}{2}}$

$\tt{\rightarrow\dfrac{539}{6}}$

= 89.83 cm^3

★CSA of Hemisphere :-

= 2πr²

$\tt{\rightarrow 2\times\dfrac{22}{7}\times\dfrac{7}{2}\times\dfrac{7}{2}}$

= 77 cm²

★TSA of Hemisphere :-

= 3πr²

$\tt{\rightarrow 3\times\dfrac{22}{7}\times\dfrac{7}{2}\times\dfrac{7}{2}}$

$\tt{\rightarrow\dfrac{231}{2}}$

= 115.5 cm²