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by d77 » Thu Dec 14, 2006 2:12 pm
A thin piece wire 40 meters long is cut into two pieces.
One piece is used to form a circle radius r,and the other is used to form a square.
No wire is left over.which of thr follwing represnts the total area in squre meters of the circular and the square regions in terms of r?

Pai*(r^2)
Pai*(r^2)+10
Pai*(r^2)+1\4(pai^2)(r^2)
Pai*(r^2)+(40-2pai*r)^2
Pai*(r^2)+(10-1\2*pai*r)^2


**e**

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by thankont » Fri Dec 15, 2006 9:49 am
Perimeter of circle Pc = 2pi*r
Perimeter of square Ps = 4y
Add them up and get 40=2pi*r+4y so
y = 10 - pi*r/2
Answer is --e--