document.write( "Question 373688: A Norman window has the shape of a semicircle atop a rectangle so that the diameter of the semicircle is equal to the width of the rectangle. The goal is to find the area of the largest possible Norman window with a perimeter of 35 feet? \n" ); document.write( "
Algebra.Com's Answer #266025 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
A Norman window has the shape of a semicircle atop a rectangle so that the
\n" ); document.write( " diameter of the semicircle is equal to the width of the rectangle.
\n" ); document.write( " The goal is to find the area of the largest possible Norman window with a
\n" ); document.write( " perimeter of 35 feet?
\n" ); document.write( ":
\n" ); document.write( "Let x = the width and diameter of the window
\n" ); document.write( "Let L = the rectangle portion length of the window
\n" ); document.write( ":
\n" ); document.write( "radius of the semicircle = .5x
\n" ); document.write( "half circumference of the semi circle = \"pi%2A.5x\" = 1.5708x
\n" ); document.write( ":
\n" ); document.write( "Perimeter:
\n" ); document.write( "1.5708x + x + 2L = 35
\n" ); document.write( "2.5708x + 2L = 35
\n" ); document.write( "2L = (35-2.5708x)
\n" ); document.write( "L = \"1%2F2\"(35-2.5708x)
\n" ); document.write( "L = 17.5 - 1.2854x
\n" ); document.write( ":
\n" ); document.write( "The area:
\n" ); document.write( "A = x * L
\n" ); document.write( "Replace L with (17.5-1.2854x)
\n" ); document.write( "A = x(17.5-1.2854x)
\n" ); document.write( "A = -1.2854x^2 - 17.5x
\n" ); document.write( "Max area occurs at the axis of symmetry of this quadratic equation
\n" ); document.write( "x = \"%28-17.5%29%2F%282%2A-1.2854%29\"
\n" ); document.write( "x = \"%28-17.5%29%2F%28-2.5708%29\"
\n" ); document.write( "x = 6.8072 ft the width that gives max area
\n" ); document.write( ":
\n" ); document.write( "Find the area, replace x with 6.8072
\n" ); document.write( "A = -1.2854(6.8072^2) + 17.5(6.8072)
\n" ); document.write( "A = -1.2854(46.3382) + 17.5(6.8072)
\n" ); document.write( "A = -59.556 + 119.126
\n" ); document.write( "A = 59.57 sq/ft, max area for 35 ft perimeter
\n" ); document.write( "
\n" ); document.write( "
\n" );