by definition, internal angles in a triangle must add up to 180°
in this case,
∠A + ∠B + ∠C = 180°
we are given ∠C = 55° and ∠A = 30°
30° + ∠B + 55° = 180°
∠B = 180 - 55 - 30 = 95° (Answer)
We can see that all 3 angles of the triangle are different. And hence we can conclude that all 3 sides of the triangle are different length (i.e it is not equilateral or isosceles). Hence it is a scalene triangle.
