



 
Hi Jason. A norman window has a semicircular top to it. Let r = the radius of the semicircle. So the perimeter is 20 = 2r + 2h + πr. Solve the first equation for h and substitute this into the second equation  that gets rid of the h and you should get a quadratic in r for the area. So solve for the maximum value of a, you have the choice of two methods:
Cheers,  


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