<PRE><B>Question 107539</B>
A circular swimming pool is surrounded by a walkway that is 2 meters wide. Find the radius of the pool if the area of the walkway is 88 m2. (Let pi = 22/7) Hint: Do not substitute the fraction for pi until near the end of the problem.) 
:
Let r = radius of the pool
Circular area which include the walkway radius = (r+2): call it the big circle
:
Big circle area - pool area = 88
(pi*(r+2)^2) - (pi*r^2) = 88
:
(pi(r^2 + 4r + 4)) - pi*r^2 = 88; FOILed (r+2)(r+2)
:
pi*r^2 + 4pi*r + 4*pi - pi*r^2 = 88
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