SOLUTION: The area of a circle is 28 π cm^2. Find the area of a circle with a radius half the length of the original circle

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Question 1107307: The area of a circle is 28 π cm^2. Find the area of a circle with a radius half the length of the original circle
Found 2 solutions by josmiceli, Alan3354:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+A+=+pi%2Ar%5E2+
+r%5E2+=+A%2Fpi+
+r+=+sqrt%28+A%2Fpi+%29+
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You are given +A+=+28%2Api+
+r+=+sqrt%28+%28+28%2Api+%29+%2F+pi+%29+
+r+=+2%2Asqrt%287%29+
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Find +A+ with +r%2F2+ radius
+A+=+pi%2A%28+r%2F2+%29%5E2+
+A+=+%28+pi%2F4+%29%2Ar%5E2+
+A+=+%28+pi%2F4+%29%2A%28+4%2A7+%29+
+A+=+7pi+
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check my math

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The area of a circle is 28pi cm^2. Find the area of a circle with a radius half the length of the original circle
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Area is a function of the square of the radius.
1/2 the radius --> (1/2)^2 the area
= 1/4 the area