Answer:
x = 8
Explanation:
We have a given triangle with two interior angles which are x + 23 and 80°. The third angle of the triangle would be equal to 4x + 17. This is because vertical angles are congruent.
Thus:
(x + 23) + 80 + (4x + 17) = 180
x + 23 + 80 + 4x + 17 = 180
5x + 120 = 180
Subtract - 120 both sides
5x = 180 - 120
5x = 40
Divide both sides by 5
x = 8