document.write( "Question 1011966: Have problems with finding the length and the ditance of a sqaure. \n" ); document.write( "
Algebra.Com's Answer #627796 by MathLover1(20849)\"\" \"About 
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14 an extension ;\r
\n" ); document.write( "\n" ); document.write( "ladder rests \"4m\" up a wall
\n" ); document.write( "If the ladder is extended a further \"0.8\" without moving the foot of the ladder, then it will now rest \"1m\" further up the wall\r
\n" ); document.write( "\n" ); document.write( " How long is the extended ladder?\r
\n" ); document.write( "\n" ); document.write( "let \"L\" = original length of the ladder
\n" ); document.write( "\"a\" = the distance of the foot of the ladder from the wall\r
\n" ); document.write( "\n" ); document.write( "\"L%5E2+=+a%5E2+%2B+4%5E2\"
\n" ); document.write( "\"L%5E2+=+a%5E2+%2B+16\"
\n" ); document.write( "\"a%5E2+=+L%5E2+-+16\" <--- eq. 1\r
\n" ); document.write( "\n" ); document.write( "\"%28L%2B0.8%29%5E2+=+a%5E2+%2B+%284%2B1%29%5E2\"\r
\n" ); document.write( "\n" ); document.write( "subs \"a%5E2\" from eq. 1\r
\n" ); document.write( "\n" ); document.write( "\"%28L%2B0.8%29%5E2+=+L%5E2+-+16+%2B+5%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"cross%28L%5E2%29+%2B+1.6L+%2B+0.64+=+cross%28L%5E2%29+-+16+%2B+25\"\r
\n" ); document.write( "\n" ); document.write( "\"1.6L+%2B+0.64+=+9\"\r
\n" ); document.write( "\n" ); document.write( "\"1.6L+=+8.36\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%28L+=+5.23m%29\"\r
\n" ); document.write( "\n" ); document.write( "\"L%2B0.8+=5.23m%2B0.8m+=6.03m\" <---- length of extended ladder\r
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\n" ); document.write( "\n" ); document.write( "15) \r
\n" ); document.write( "\n" ); document.write( "an equilateral triangle has area \"A=16sqrt%283%29cm%5E2\".
\n" ); document.write( "Find the length of its sides.\r
\n" ); document.write( "\n" ); document.write( "\"A+=+%281%2F2%29bh\"\r
\n" ); document.write( "\n" ); document.write( "\"16%2Asqrt%283%29+=+%281%2F2%29bh\"\r
\n" ); document.write( "\n" ); document.write( "\"bh+=+32sqrt%283%29\".........eq.1\r
\n" ); document.write( "\n" ); document.write( "-----------
\n" ); document.write( "Find altitude \"h\" in terms of side \"b\":\r
\n" ); document.write( "\n" ); document.write( "Since the triangle is equilateral, all sides are \"\"b\"\":
\n" ); document.write( "Draw an altitude from the vertex to the base.
\n" ); document.write( "You have a right triangle with base = \"b%2F2\" and hypotenuse = \"b\"
\n" ); document.write( "The altitude is the 3rd side:\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2+=+%28b%2F2%29%5E2+%2B+h%5E2\"
\n" ); document.write( "\"b%5E2-%28b%2F2%29%5E2+=+h%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2-b%5E2%2F4+=+h%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"%283%2F4%29b%5E2+=+h%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"sqrt%28%283%2F4%29b%5E2%29+=+h\"\r
\n" ); document.write( "\n" ); document.write( "\"%28sqrt%283%29%2F2%29b+=+h\"\r
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\n" ); document.write( "\n" ); document.write( "substitute in eq.1\r
\n" ); document.write( "\n" ); document.write( "\"bh+=+32sqrt%283%29\"\r
\n" ); document.write( "\n" ); document.write( "\"b%2A%28sqrt%283%29%2F2%29b+=+32sqrt%283%29\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2=+32sqrt%283%29%2F%28sqrt%283%29%2F2%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2=+%282%2A32cross%28sqrt%283%29%29%29%2Fcross%28sqrt%283%29%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"b%5E2=+64+\"\r
\n" ); document.write( "\n" ); document.write( "\"b=sqrt%2864%29\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%28b=8%29\"->the length of each side\r
\n" ); document.write( "\n" ); document.write( "and now we can find the length of altitude too:\r
\n" ); document.write( "\n" ); document.write( "\"%28sqrt%283%29%2F2%298+=+h\"\r
\n" ); document.write( "\n" ); document.write( "\"4%2Asqrt%283%29=+h\"\r
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\n" ); document.write( "\n" ); document.write( "check the area:\r
\n" ); document.write( "\n" ); document.write( "\"A+=+%281%2F2%29bh\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+%281%2F2%298%2A4%2Asqrt%283%29\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+%281%2Fcross%282%291%29cross%288%294%2A4%2Asqrt%283%29\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+16sqrt%283%29\" which confirms our solution\r
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