Hi!
These two angles are alternate interior angles, so they are congruent. Thus:
∠A = ∠B
6x + 5 = 4x + 45
Solve for x:
2x + 5 = 45
2x = 40
x = 20
Solve for ∠A by substituting in this value:
∠A = 6(20) + 5 = 125°
4.5m questions
5.9m answers