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

m∠A = 15° and m∠C = 35°
m∠A + m∠B = 155°
m∠A + m∠C = 60°
m∠A = 20° and m∠C = 30°

m∠A + m∠B = 155

Step-by-step explanation:

ABC is an isosceles triangle that has a 130° angle at vertex B

then

m∠A = (180 - 130)/2 = 50/2 = 25 = m∠C

then

m∠A = m∠C = 25°

you could deduce the conclusion directly using the facts pertaining to the specific situation.

hope this .