Answer:
Angle B = 131 degrees
Step-by-step explanation:
We know that since there's an angle labeled 139 degrees and a straight line is 180 degrees in total, the other angle is equal to 180 - 139 = 41 degrees.
Since all triangles have 3 angles that add up to 180 degrees and we know that theres a right angle, a 41 degree angle, then angle A must equal to 180 - 41 - 90 = 49 degrees.
We know that vertical angles are congruent, therefore angle C is also equal to 49 degrees.
Angle B and angle A form a straight line, which we have defined as 180 degrees.
180 - 49 = 131 degrees.
Angle B = 131 degrees
