document.write( "Question 982145: In a triangle DEF, m〈E is three times m 〈D, and m〈F is 9 less than m〈E. What is the measure of each angle? Thank u \n" ); document.write( "
Algebra.Com's Answer #603000 by ikleyn(52834)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Let  x  be the measure of the angle  LD:   x = m(LD)  (in degrees).\r
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\n" ); document.write( "\n" ); document.write( "Then the measure of the angle  LE  be  3x,  and the measure of the angle  LF  be  3x - 9°  degrees.\r
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\n" ); document.write( "\n" ); document.write( "Since the sum of interior angles of a triangle is equal to 180°,  you have an equation\r
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\n" ); document.write( "\n" ); document.write( "x + 3x + (3x - 9) = 180.\r
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\n" ); document.write( "\n" ); document.write( "Simplify and solve it:\r
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\n" ); document.write( "\n" ); document.write( "7x - 9 = 180,\r
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\n" ); document.write( "\n" ); document.write( "7x = 180 + 9,\r
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\n" ); document.write( "\n" ); document.write( "7x = 189,\r
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\n" ); document.write( "\n" ); document.write( "x = \"189%2F7\" = 27°.\r
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\n" ); document.write( "\n" ); document.write( "Hence,  m(LD) = 27°,  m(LE) = 3*27° = 81°, and  m(LE) = 81° - 9° = 72°.\r
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