11)

The inscribed angles are 25 degrees and 65 degrees. The angle x is part of a triangle formed by two radii and a chord. The angle at the center subtended by the arc is 25 + 65 = 90 degrees. The angle x is the remaining angle in the triangle formed by the radii and the chord. The two radii are equal, so it's an isosceles triangle. The angle opposite the chord is 180 - 90 = 90 degrees. The other two angles are equal: x = (180 - 90) / 2 = 45 degrees.