document.write( "Question 1105588: Equilateral triangle ABC has altitude AD. Median AE of triangle ABD is drawn. If the area of triangle AEC is 27√3 cm2. What is the side lenght AB, in cm?
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Algebra.Com's Answer #720489 by KMST(5328)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "An equilateral triangle with side length \"x\" has a height \"%28sqrt%283%29%2F2%29x\"
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\n" ); document.write( "and an area \"%28sqrt%283%29%2F4%29x%5E2\",
\n" ); document.write( "so if \"x\" represents the length of side AB in cm, \"%28sqrt%283%29%2F4%29x%5E2\" is the area of ABC in \"cm%5E2\" .
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\n" ); document.write( "The altitude of an equilateral triangle is also a median,
\n" ); document.write( "so it splits the triangle into two triangles with the same area.
\n" ); document.write( "Those triangles are ABD and ACD, each with an area equal to {1/2}}} of the area of ABC.
\n" ); document.write( "Triangle ABD is similarly split into triangles ABE and AED,
\n" ); document.write( "each with area equal to \"1%2F2\"of the area of ABD,
\n" ); document.write( "meaning \"1%2F4\" of the area of ABC.
\n" ); document.write( "Triangle ARC is the union of triangles ABD and AED,
\n" ); document.write( "so its area is \"1%2F2%2B1%2F4=3%2F4\" of the area of ABC.
\n" ); document.write( "That is
\n" ); document.write( "\"%283%2F4%29%28sqrt%283%29%2F4%29x%5E2=%283sqrt%283%29%2F16%29x%5E2\" .
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\n" ); document.write( "\"%283sqrt%283%29%2F16%29x%5E2=27sqrt%283%29\"
\n" ); document.write( "\"%283%2F16%29x%5E2=27\"
\n" ); document.write( "\"x%5E2=27%2A16%2F3\"
\n" ); document.write( "\"x%5E2=9%2A16\"
\n" ); document.write( "\"x=sqrt%289%2A16%29=sqrt%289%29sqrt%2816%29r3%2A4=highlight%2812%29\" .
\n" ); document.write( "The length of side AB is \"highlight%2812cm%29\" .
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