Answer:
mAngle B =70°
Step-by-step explanation:
The question says to find the "measure of Angle B"
The triangle there is an isosceles triangle. That means two of the sides are the same size. The angles opposite from those equal sides are also equal.
BA = BC = 40cm
So Angle A = Angle C = 55°
All three angles in a triangle add up to 180°
55 + 55 + B = 180
110 + B = 180
B = 70°
The measure of angle B is 70°
