Magnification 21383

When we increased the circle's radius by 2 cm, its area increased by 40π cm2. Determine the radius of the circle before magnification.

Correct answer:

r =  9 cm

Step-by-step explanation:

π   (r+2)2 = π r2 + 40pi (r+2)2 = r2 + 40  4r=36  4 r=36  4r=36  r=436=9  r=9=9 cm



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