Find the surface area of a ball of radius 21 mm. (Use π=
7
22
)
- A5540 mm
2 - B5546 mm
2 - C5544 mm
2 - D5542 mm
2
Solution & Step-by-step Explanation
A ball is spherical in shape. The total surface area (A) of a sphere is given by the formula:
A=4πr
2
Given:
Radius, r=21 mm
π=
7
22
Substituting the values into the formula:
A=4×
7
22
×21×21
A=4×22×3×21
A=88×63
A=5544 mm
2
A=4πr
2
Given:
Radius, r=21 mm
π=
7
22
Substituting the values into the formula:
A=4×
7
22
×21×21
A=4×22×3×21
A=88×63
A=5544 mm
2