9514 1404 393
Answer:
70°
Explanation:
Angles 2 and 13 are alternate exterior angles, so are congruent. The value of x can be found by solving the equation that equates the expressions for the measures of these angles. Once x is found, the measure of angle 13 can be determined. The measure of angle 9 is the supplement of angle 13.
So, ...
m∠2 = m∠13
8x +14 = 10x -10
24 = 2x . . . . . . . . add 10-2x
12 = x
m∠13 = 10x -10 = 10·12 -10 = 110
m∠9 = 180° -110°
m∠9 = 70°