Answer:
33.53
Explanation:
OB is a radius of the circle, and OC is also a radius of the circle, so both are equal length. That makes ΔOBC an isosceles triangle.
If we cut ΔOBC in half, the angle formed is 125° / 2 = 62.5°.
Therefore:
sin 62.5 = (x/2) / 18.9
x = 37.8 sin 62.5
x ≈ 33.53