document.write( "Question 924424: if the vertex of an isosceles triangle is 80 degrees and the side opposite the vertex measures 12 cm, determine the perimeter of the triangle.
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Algebra.Com's Answer #560830 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!
you can solve it this way:\r
\n" ); document.write( "\n" ); document.write( "An isosceles triangle can be considered as two right angle triangles joined together so use the tangent ratio to find its altitude \"h\":\r
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\n" ); document.write( "\n" ); document.write( "given angle \"B+=80\"=> angle \"A+=C=50\"
\n" ); document.write( "base \"b=12cm\"\r
\n" ); document.write( "\n" ); document.write( "\"tan%2850+%29+=+h%2F%286cm%29\" (where \"h\" is the altitude and \"6cm\" is half the base)\r
\n" ); document.write( "\n" ); document.write( "\"tan%2850+%29+=+h%2F%286cm%29\"\r
\n" ); document.write( "\n" ); document.write( "\"1.1918=+h%2F%286cm%29\"\r
\n" ); document.write( "\n" ); document.write( "\"1.1918%2A6cm=+h\"\r
\n" ); document.write( "\n" ); document.write( "\"7.15cm=+h\"\r
\n" ); document.write( "\n" ); document.write( "now we can find \"a\" using Pythagorean theorem:\r
\n" ); document.write( "\n" ); document.write( "\"a%5E2=%28b%2F2%29%5E2%2Bh%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"a%5E2=%286cm%29%5E2%2B%287.15cm%29%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"a%5E2=36cm%5E2%2B51cm%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"a%5E2=87cm%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"a=sqrt%2887cm%5E2%29\"\r
\n" ); document.write( "\n" ); document.write( "\"a=9.33cm\"\r
\n" ); document.write( "\n" ); document.write( "\"P=2a%2Bb\" (triangle is isosceles, \"a=c\")\r
\n" ); document.write( "\n" ); document.write( "\"P=2%2A9.33cm%2B12cm\"\r
\n" ); document.write( "\n" ); document.write( "\"P=18.66cm%2B12cm\"\r
\n" ); document.write( "\n" ); document.write( "\"P=30.66cm\"\r
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