SOLUTION: What is the surface area of a sphere if a hemisphere with the same radius had a surface area of 69π cm^2

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Question 1109981: What is the surface area of a sphere if a hemisphere with the same radius had a surface area of 69π cm^2
Found 2 solutions by ikleyn, greenestamps:
Answer by ikleyn(52894) About Me  (Show Source):
You can put this solution on YOUR website!
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A sphere is comprised of 2 (two, TWO) hemispheres.


Answer by greenestamps(13209) About Me  (Show Source):
You can put this solution on YOUR website!


The formula for the surface area of a sphere is
4%28pi%29%28r%5E2%29

On a hemisphere, the curved surface area is therefore 2%28pi%29%28r%5E2%29 and the flat surface area is %28pi%29r%5E2%29, so the total surface area is 3%28pi%29%28r%5E2%29.

So the surface area of the sphere is 4/3 the surface area of the hemisphere.

%2869pi%29%2A%284%2F3%29+=+92pi

The surface area of the sphere is 92pi cm^2.