document.write( "Question 862621: please help me in finding the Internal angles of a Triangle when the external angle is given as 75 \n" ); document.write( "
Algebra.Com's Answer #519777 by rothauserc(4718)\"\" \"About 
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we have two equations, let x, y, z be the internal angles of the triangle and w be the external angle with z, then we have
\n" ); document.write( "x + y + z = 180
\n" ); document.write( "w + z = 180
\n" ); document.write( "solve second equation for z
\n" ); document.write( "z = 180 - w
\n" ); document.write( "now substitute for z in first equation
\n" ); document.write( "x + y + (180 - w) = 180
\n" ); document.write( "x + y - w = 0
\n" ); document.write( "w = x + y
\n" ); document.write( "we know w = 75 degrees and
\n" ); document.write( "z + 75 = 180
\n" ); document.write( "z = 105 and x+y = 75\r
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