\r\n" );
document.write( "
\r\n" );
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document.write( "We calculate GE by using the Pythagorean theorem on right triangle FGE.\r\n" );
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document.write( "
\r\n" );
document.write( "AG is also
, so diagonal of the rhombus, AE =
\r\n" );
document.write( "FG = GD = 5 so the other diagonal of the rhombus, FD is 10.\r\n" );
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document.write( "The area of a rhombus is
the product of the diagonals, or,\r\n" );
document.write( "Area of rhombus ADEF is
.\r\n" );
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document.write( "Since ABCF is a parallellogram, \r\n" );
document.write( "ABCD is an isosceles trapezoid (or trapezium if you live in the UK).\r\n" );
document.write( "We draw two green lines at D and C perpendicular to AB and CD. They partition\r\n" );
document.write( "the trapezoid into two congruent right triangles, and a rectangle in the middle.\r\n" );
document.write( "Since AH = GD = 5, the area of right triangle AHD is\r\n" );
document.write( "
\r\n" );
document.write( "The area of right triangle BIC is also
\r\n" );
document.write( "All that's left of isosceles trapezoid ABCD is the area of rectangle HICD which\r\n" );
document.write( "is
\r\n" );
document.write( "Area of rectangle =
\r\n" );
document.write( "Area of right triangle BIC =
\r\n" );
document.write( "Area of isosceles trapezoid ABCD =
\r\n" );
document.write( "\r\n" );
document.write( "Area of rhombus ADEF =
\r\n" );
document.write( "Area of isosceles trapezoid ABCD =
\r\n" );
document.write( "\r\n" );
document.write( "Area of composite figure =
\r\n" );
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document.write( "That's approximately 422.4 sqruare units.\r\n" );
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document.write( "Edwin
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document.write( "