Question

If isosceles triangle ABC has a 130° angle at vertex B, which statement must be true?

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Answer 1

the some of an Isosceles triangle is 180.

if vertex B = 130 degrees then the other two must be equal 50 degrees. so you divided 50 by 2 which equals 25.

in this case you have 2 points which equal 50. so you take the one which is the closest to 25. which is the last point. m<A = 20 and m<C + 30.
I hope this is right.