Answer:
U = 71 degrees
Step-by-step explanation:
First you should set up an equation:
180 = b + (b - 19) + (180 - (b + 45))
Since there are 180 degrees in a triangle, set the sum of the angles equal to 180. And, since (u) and (b + 45) are supplementary angles that add up to 180, you can substitute (180 - (b + 45)) for (u).
Then, solve for (b):
180 = b + b - 19 + 180 - b - 45
180 = b + 116
64 = b
Find (b + 45):
64 + 45 = 109
Solve for (u):
180 - 109 = 71
u = 71
