document.write( "Question 86386: Alan is building a garden shaped like a rectangle with a semicircle attached to one short side. If he has 70 feet of fencing to go around it, what dimensions will give him the maximum area in the garden?\r
\n" ); document.write( "\n" ); document.write( "I know that eventually you may have to use the X=b/2a formula
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #62504 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Alan is building a garden shaped like a rectangle with a semicircle attached to one short side. If he has 70 feet of fencing to go around it, what dimensions will give him the maximum area in the garden?
\n" ); document.write( "----------------
\n" ); document.write( "Draw the picture.
\n" ); document.write( "Let the shorter side be \"x\"
\n" ); document.write( "Perimeter of the semi-circle is (pi)x
\n" ); document.write( "Twice the Length of the longer side is [70-(pi)x -x]
\n" ); document.write( "Length = [70-(1+pi)x]/2
\n" ); document.write( "Total area = area of rectangle + area of the semi-circle.
\n" ); document.write( "Total area = x[[70-(1+pi)x]/2] + [(pi)(x/2)^2]/2
\n" ); document.write( "2Total area = 70x -(1+pi)x^2 + [(pi)(x^2/4)]
\n" ); document.write( "2Total area = 70x +[(pi/4)-(1+pi)]x^2
\n" ); document.write( "2Total area = 70x - [3.3562]x^2
\n" ); document.write( "Total area = 35x - 1.6781x^2
\n" ); document.write( "-------------
\n" ); document.write( "Max occurs at x = 35/2*1.6781= 20.8569(shorter side)
\n" ); document.write( "Longer side = [70-(1+pi)*10.4285]/2 = 13.4047 (longer side)
\n" ); document.write( "================
\n" ); document.write( "Comment: The method here is correct; the arithmetic may be less
\n" ); document.write( "than the accuracy you require. I recommend you check it out.
\n" ); document.write( "---------
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "
\n" ); document.write( "
\n" );