Question 178000
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Let one of the base angles be <i>x</i>.  Then the other base angle must be <i>x</i> also.  The vertex angle is 20 degrees larger, so it must be <i>x</i> + 20.  We know the sum of the three interior angles of a triangle to be 180 degrees, so:


*[tex \Large x + x + (x + 20) = 180]


*[tex \Large 3x + 20 = 180]


*[tex \Large 3x = 160]


*[tex \Large x = \frac {160}{3}]


So the two base angles are *[tex \Large \frac {160}{3} = 53\frac{1}{3}] degrees and the vertex angle must be *[tex \Large \frac {220}{3} = 73\frac{1}{3}] degrees.


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