Question

find the total surface area of a hemisphere with radius 20 cm​

Answer 1

Given :

• Radius of Hemishphere = 20cm.

To Find :

• Total Surface Area of Hemisphere.

Solution :

$\longmapsto\tt{Radius=20cm}$

Using Formula :

$\longmapsto\tt\boxed{T.S.A\:of\:Hemisphere=3\pi{{r}^{2}}}$

Putting Values :

$\longmapsto\tt{3\times\dfrac{22}{7}\times{20}\times{20}}$

$\longmapsto\tt{\cancel\dfrac{26400}{7}}$

$\longmapsto\tt\bold{3771.4{cm}^{2}(Approx.)}$

So , The T.S.A of Hemisphere is 3771.4cm² .

_______________________

• C.S.A of Hemisphere = 2πr²
• T.S.A of Hemisphere = 3πr²
• Volume of Hemishphere = 2/3πr³
• Surface Area of Sphere = 4πr²
• Volume of Sphere = 4/3πr³

_______________________

Answer 2

Answer: 3768 cm²

Step-by-step explanation:

Radius = r = 20cm

Total surface area of hemisphere = 3πr²

= 3 × 22/7 × 20 × 20

= 26400/7

= 3771.42

= 3771.5 cm²