Respuesta :

25 because a triangle is 180 so those two angles equal 155 180-155 is 25

Answer:

25°

Step-by-step explanation:

A triangle will always add up to 180 degrees when all angles are added.

So:

100 + 55 = 155

180 - 155 = ∠B

180 - 155 = 25

∠B = 25°