document.write( "Question 1073352: 4 semicircle and 4 quadrant each of radius 7cm were cut off from a rectangular cardboard if perimeter 128cm.Find the perimeter of the cut cardboard. \n" ); document.write( "
Algebra.Com's Answer #688187 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
Without more detail, some assumptions need to be made.
\n" ); document.write( "
\n" ); document.write( "1) For starters, we need a conveniently shaped rectangle,
\n" ); document.write( "with enough usable surface area, such as a 16 cm by 48 cm rectangle.
\n" ); document.write( "Not all rectangles with a perimeter of 128 cm will yield
\n" ); document.write( "4 semicircles and 4 quadrants each of radius 7cm.
\n" ); document.write( "For example, a rectangle of with 8 cm and length 56 cm has a perimeter of
\n" ); document.write( "\"2%285cm%2B56cm%29=2%2A64cm=128cm\" ,
\n" ); document.write( "but it cannot yield 4 semicircles and 4 quadrants each of radius 7cm,
\n" ); document.write( "not even reshaping the cutouts to make circular sectors out of the wasted cutout pieces.
\n" ); document.write( "That rectangle has an area of
\n" ); document.write( "\"%2856cm%29%288cm%29=488cm%5E2\" ,
\n" ); document.write( "while 4 semicircles and 4 quadrants each of radius 7cm
\n" ); document.write( "add to a larger total surface area.
\n" ); document.write( "They have the same total area as the 3 circles of radius 7cm they would form,
\n" ); document.write( "\"3%2Api%2A%287cm%29%5E2=about+461.8cm%5E2\" .
\n" ); document.write( "
\n" ); document.write( "2) Then, there is the issue of where to cut from.
\n" ); document.write( "One practical way, would be to cut the quadrants from the corners,
\n" ); document.write( "and the semicircles along the long edges of the rectangle,
\n" ); document.write( "with the straight sector edges along the sides of the rectangle,
\n" ); document.write( "like this:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "With the assumptions above about
\n" ); document.write( "1) the shape of the rectangle, and
\n" ); document.write( "2) the way the circular sectors were cut off,
\n" ); document.write( "we are left with a piece that has for perimeter
\n" ); document.write( "some segments of the rectangle's straight edges, and
\n" ); document.write( "the curved edges of 3 circles.
\n" ); document.write( "The curved edges of 3 circles add up to
\n" ); document.write( "\"3%282pi%287cm%29%29=pi%2A42cm=about131.95cm\"
\n" ); document.write( "For each circular sector piece cut off,
\n" ); document.write( "the removed segment(s) of the rectangle's edges were
\n" ); document.write( "\"2%2A7cm=14cm\"
\n" ); document.write( "So what's left as straight segments of the rectangle's original perimeter is
\n" ); document.write( "\"128cm-8%2A14cm=128cm-112cm=16cm\"
\n" ); document.write( "So the straight plus curved parts of the perimeter of the
\n" ); document.write( "piece leftoever of the rectangle is approximately
\n" ); document.write( "\"16cm%2B131.95cm=highlight%28147.95cm%29\" .
\n" ); document.write( "If an exact expression is required, it would be
\n" ); document.write( "\"16cm%2Bpi%2A42cm=highlight%2816%2B42pi%29cm\"
\n" ); document.write( "
\n" );