We are asked to solve for the value of "x" in the problem. In the circle property, assuming that S is the diameter of the circle, we can say that the angle facing the diameter is 90°.
We have the summation of all angles in a triangle equal to 180°. Solving for x, we have: 180 ° = x + 90° + 39° x = 180° - 90° -39° x = 51°