B = 119 degrees
A straight line is 180 degrees
The 112 degree angle and angle C make up a straight line, so 112+C = 180
c = 68 degrees
The sum of a triangle’s angles also equal 180 degrees, so angle A + angle B + angle C =180
This means 51 + 68 + A = 180
119+A=180
A = 61 degrees
Now knowing angle A, and knowing that a straight line is 180 degrees, you can solve for angle B
A+B =180
61+B=180
B=119 Degrees
