Answer:
117 degrees
Explanation:
Two vertical angles will always equal each other.
So, set up an equation where angle A and angle B equal each other to solve for x:
5x - 3 = 4x + 21
5x = 4x + 24
x = 24
Plug in 24 for x in the expression represent angle A:
5(24) - 3
120 - 3
117