document.write( "Question 574813: Two Parallel sides DC & AB of a trapezium are 12 cm and 36 cm respectively. If non parallel sides are 15 cm each.Find the area of the trapezium? \n" ); document.write( "

Algebra.Com's Answer #369313 by Edwin McCravy(20056) $\"\"$ $\"About$

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document.write( "The trapezoid (the US word for the UK word \"trapezium\") \r\n" );
document.write( "is isosceles:\r\n" );
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document.write( "We will draw altitudes AF and BE  (in green) perpendicuilar to DC.  Since\r\n" );
document.write( "EF = AB = 12cm, and 12cm is  of DC which is 36cm, DF amd EC are also\r\n" );
document.write( "12cm each.\r\n" );
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document.write( "We can find altitude AF by applying the Pythagorean theorem to right \r\n" );
document.write( "triangle ADF:\r\n" );
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document.write( "                    AF² + DF² = AD²\r\n" );
document.write( "                    AF² + 12² = 15²\r\n" );
document.write( "                    AF² + 144 = 225\r\n" );
document.write( "                          AF² = 81\r\n" );
document.write( "                           AF = 9cm\r\n" );
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document.write( "          Area =(Average of parallel sides)·(altitude)\r\n" );
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document.write( "          Area = ·AF\r\n" );
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document.write( "          Area = ·9cm\r\n" );
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document.write( "          Area = ·9cm\r\n" );
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document.write( "          Area = 24cm·9cm\r\n" );
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document.write( "          Area = 216cm²\r\n" );
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document.write( "Edwin

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