SOLUTION: If AB=AC and m<A=100° what us the measure of <b in degrees

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Question 696909: If AB=AC and m
Answer by MathLover1(20849) About Me  (Show Source):
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if AB=AC and m< a=100° what is the measure of m < b in degrees
if AB=AC...=> you have an isosceles triangle and m < b is equal to m < c
since the three angles in triangle always add to 180°, we have
a%2Bb%2Bc=180°........since m < b = m < c

100%2Bb%2Bb=180°
2b=180-100°
2b=80°
b=80%2F2°
b=40° and m < c=40° too