document.write( "Question 982458: sir, maam
\n" ); document.write( "good day pls help me with my homework pls i need to answer this in 3 hour because i am confused so that i cannot do it on my house pls help me \r
\n" ); document.write( "\n" ); document.write( "1.Two altitudes of an isosceles triangle areequal to 20 cm and 30 cm. Determine the baseangles of the triangle\\r
\n" ); document.write( "\n" ); document.write( "2.Two altitudes of an isosceles triangle areequal to 20 cm and 30 cm. Determine the baseangles of the triangle
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Algebra.Com's Answer #603302 by ikleyn(52786)\"\" \"About 
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\n" ); document.write( "1.  First,  let us assume that the altitude of  20 cm  long goes  to the base  \"b\"  and the altitude of  30 cm  long goes to the lateral side  \"a\".\r
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\n" ); document.write( "\n" ); document.write( "Then you have these expressions for the area of the triangle:\r
\n" ); document.write( "\n" ); document.write( "\"S\" = \"1%2F2\".\"b%2A20\" = \"1%2F2\".\"a%2A30\".\r
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\n" ); document.write( "\n" ); document.write( "It implies that  \"b%2A20\" = \"a%2A30\".\r
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\n" ); document.write( "\n" ); document.write( "Hence,  \"b\" = \"a%2A%2830%2F20%29\" = \"a%2A%283%2F2%29\".\r
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\n" ); document.write( "\n" ); document.write( "Now consider the right-angled triangle formed by the base,  by the altitude of  20 cm  long and by the lateral side  \"a\".\r
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\n" ); document.write( "\n" ); document.write( "This right-angled triangle has the hypotenuse of the length  \"a\"  and the leg of the length  \"b%2F2\"  (yes,  it is half of the base of the triangle,  \"b%2F2\" = \"a%2A%283%2F4%29\"). \r
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\n" ); document.write( "\n" ); document.write( "I believe  (I hope)  you just made a sketch of your triangle.  It will help you to see what I am saying.\r
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\n" ); document.write( "\n" ); document.write( "Therefore,  \"cos%28alpha%29\" = \"%28b%2F2%29%2Fa\" = \"%28a%2A%283%2F4%29%29%2Fa\" = \"3%2F4\",  where  \"alpha\"  is the angle at the base of our isosceles triangle. \r
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\n" ); document.write( "\n" ); document.write( "Thus,  in this case \"cos%28alpha%29\" = \"3%2F4\" and \"alpha\" = \"arccos%283%2F4%29\". \r
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\n" ); document.write( "\n" ); document.write( "2.  Next, let us consider the other configuration when the altitude of  30 cm  long goes  to the base  \"b\"  and the altitude of  20 cm  long goes to the lateral side  \"a\".\r
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\n" ); document.write( "\n" ); document.write( "Then you have these expressions for the area of the triangle:\r
\n" ); document.write( "\n" ); document.write( "\"S\" = \"1%2F2\".\"b%2A30\" = \"1%2F2\".\"a%2A20\".\r
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\n" ); document.write( "\n" ); document.write( "It implies that  \"b%2A30\" = \"a%2A20\".\r
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\n" ); document.write( "\n" ); document.write( "Hence,  \"b\" = \"a%2A%2820%2F30%29\" = \"a%2A%282%2F3%29\".\r
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\n" ); document.write( "\n" ); document.write( "Now consider the right-angled triangle formed by the base,  by the altitude of  30 cm  long and by the lateral side  \"a\".\r
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\n" ); document.write( "\n" ); document.write( "This right-angled triangle has the hypotenuse of the length  \"a\"  and the leg of the length  \"b%2F2\"  (which is half of the base of the triangle, \"b%2F2\" = \"a%2A%282%2F6%29\") = \"a%2A%281%2F3%29\". \r
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\n" ); document.write( "\n" ); document.write( "Again, I hope you just made a sketch of your triangle. \r
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\n" ); document.write( "\n" ); document.write( "Therefore,  \"cos%28alpha%29\" = \"%28b%2F2%29%2Fa\" = \"%28a%2A%281%2F3%29%29%2Fa\" = \"1%2F3\". \r
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\n" ); document.write( "\n" ); document.write( "Thus,  in this case \"cos%28alpha%29\" = \"1%2F3\" and \"alpha\" = \"arccos%281%2F3%29\". \r
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\n" ); document.write( "\n" ); document.write( "Answer.  \"alpha\" = \"arccos%281%2F3%29\"  or  \"alpha\" = \"arccos%283%2F4%29\". \r
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