Question

The total surface area of a hemisphere is
4158 cm 2; find the circumference of its
base.​

Answer 1

Given

Surface Area of a hemisphere=4158 cm²

Solution

The total surface area of the hemisphere is SA=3πr².

Where,r is the radius of hemisphere.

and SA=4158 square cm is the surface area.

Substituting the value in the formula,

4158=3πr²

4158/3π=r²

r²=441

r=√441

r=21

The diameter is d=2r=2(21)=42

Answer 2

Answer:

The diameter is 42 cm.

Step-by-step explanation:

Given : The total surface area of hemisphere is 4158 square cm.

To find : Its diameter ?

Solution :

The total surface area of the hemisphere is SA=3\pi r^2SA=3πr2

Where, r is the radius of hemisphere

SA=4158 square cm is the surface area

Substitute the value in the formula,

4158=3\pi r^24158=3πr2

\frac{4158}{3\pi}=r^23π4158=r2

r^2=441r2=441

r=\sqrt{441}r=441

r=21r=21

The diameter is d=2r=2(21)=42d=2r=2(21)=42

Therefore, The diameter is 42 cm.