Question 973630
[18x-15- (8x+1]/2)= 4x   The angle is equal to half the difference of the arcs.

18x-15-8x-1=10x-16

(10x-16)/2=5x-8

5x-8=4x
x=8

4x=32, the angle desired.

The arcs are 129, the larger, and 65, the smaller.

Their difference is 64 degrees, and half of that (32 degrees) is the angle needed.