document.write( "Question 28822: The measure of the second angle of a triangle is 12 degrees greater then three times the first angle. The measure of the third angle is 6 degrees less than twice the measure of the second angle. What are the measures of the three angles?\r
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Algebra.Com's Answer #15722 by sdmmadam@yahoo.com(530)![]() ![]() ![]() You can put this solution on YOUR website! The measure of the second angle of a triangle is 12 degrees greater then three times the first angle. The measure of the third angle is 6 degrees less than twice the measure of the second angle. What are the measures of the three angles?\r \n" ); document.write( "\n" ); document.write( "Let the first angle be A degrees, \n" ); document.write( "the second angle be B degrees and \n" ); document.write( "the third angle be C degrees. \n" ); document.write( "The second angle is 12 degrees greater than three times first angle. \n" ); document.write( "B is 12 more than 3A \n" ); document.write( "That is B= 3A+12 ----(1) \n" ); document.write( "The third angle is 6 less than twice the second angle. \n" ); document.write( "C is 6 less than 2B \n" ); document.write( "C=2B-6 ----(2) \n" ); document.write( "A,B and C being the angles of a triangle ABC, \n" ); document.write( "we have A + B + C = 180 degrees. ----(*) \n" ); document.write( "Using (1) and (2) in (*) \n" ); document.write( "A +(3A+12)+(2B-6) =180 \n" ); document.write( "A+3A +12-6+2B=180 \n" ); document.write( "4A+6+2B=180 \n" ); document.write( "4A+2B= 180-6 \n" ); document.write( "4A+2B= 174 \n" ); document.write( "4A+ 2(3A+12) =174 using (1) and substituting for B in terms of A \n" ); document.write( "4A+6A+24 =174 \n" ); document.write( "10A=174-24 \n" ); document.write( "10A = 150 \n" ); document.write( "A = 150/10 = 15 \n" ); document.write( "A= 15 in (1),then B= 3A+12 = 3X15+12 = 45+12 =57 \n" ); document.write( "Putting B= 57 in (2), \n" ); document.write( "C=2B-6 = 2X57-6 = 114-6 = 108 \n" ); document.write( "Therefore the angles are 15 deg, 57 deg and 108 deg respectively. \n" ); document.write( "Verification: Obviously they are adding up to 180 beautifully. Good\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |