Question

1.) In triangle ABC, the measure of A is 70°. Angle B is congruent to angle C. What is the measure of angle B in degrees.

Answer 1

In a triangle, the three interior angles always add to 180°

m∠B = (180-70)/2 = 55°

Answer 2

You can find the answer by taking 180 and subtracting 70 from it. Then divide that answer by two.

180-70=110. 
110/2=55

Angle B is 55 degrees. Since Angle B and Angle C are congruent, Angle C is also 55.