SOLUTION: The surface area of a cylinder is 200 cm^2. The diameter is equal to the height. Find the radius.

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Question 433993: The surface area of a cylinder is 200 cm^2. The diameter is equal to the height. Find the radius.
Found 3 solutions by Alan3354, Gogonati, robertb:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Is that the lateral area? Or does it include the top and bottom?

Answer by Gogonati(855) About Me  (Show Source):
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As we know the surface area of cylinder is %28pi%29%2AD%2AH, where D is the
diameter, and H is the height of cylinder, since H=D we can write:
200=%28pi%29%2AD%5E2, solving this equation we find D=sqrt%28200%2F%28pi%29%29 and
the radius R=D%2F2, R=%281%2F2%29%2Asqrt%28200%2F%28pi%29%29, rationalizing we find,
R=5%2Asqrt%282%29%2F%28sqrt%28pi%29%29=5%2Asqrt%282%2Api%29%2F%28pi%29.

Answer by robertb(5830) About Me  (Show Source):
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Unless it is specifically mentioned that it is lateral surface area, the surface area mentioned is TOTAL, and so

Hence %283pi%2Ad%5E2%29%2F2+=+200==> d%5E2+=+400%2F%283pi%29
==> d+=+200%2Fsqrt%283pi%29 cm
==> r+=+100%2Fsqrt%283pi%29 cm.