How to find the surface area of a sphere - GRE Quantitative Reasoning
Card 0 of 3
A sphere has a surface area of 
square inches. If the radius is doubled, what is the surface area of the larger sphere?
A sphere has a surface area of
The surface area of the larger sphere is NOT merely doubled from the smaller sphere, so we cannot double 
to find the answer.
We can use the surface area formula to find the radius of the original sphere.
_r_2 = 4
r = 2
Therefore the larger sphere has a radius of 2 * 2 = 4.
The new surface area is then 
square inches.
The surface area of the larger sphere is NOT merely doubled from the smaller sphere, so we cannot double
We can use the surface area formula to find the radius of the original sphere.
_r_2 = 4
r = 2
Therefore the larger sphere has a radius of 2 * 2 = 4.
The new surface area is then
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Find the surface area of a sphere with a diameter of 14. Use π = 22/7.
Find the surface area of a sphere with a diameter of 14. Use π = 22/7.
Surface Area = 4_πr_2 = 4 * 22/7 * 72 = 616
Surface Area = 4_πr_2 = 4 * 22/7 * 72 = 616
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If a sphere has a volume of 
cubic inches, what is its surface area?
If a sphere has a volume of
The volume of a cube is equal to 
.
So we mutiply our volume by 
and divide by 
, giving us 
.
The surface area of a sphere is equal to 
, giving us 
.
The volume of a cube is equal to
So we mutiply our volume by
The surface area of a sphere is equal to
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