Circle Z is shown. Line segments Z T, Z U, and Z V are radii of the circle. Line segment U X goes through point X and is a diameter. Line segment W Y goes from one side to the opposite side and intersects line segment U X at point S. Line segment W X is a secant. Angle X W X is 42 degrees, angle W S Y is 100 degrees, and angle T Z U is 79 degrees. Complete the statements about circle Z. A central angle, such as angle of circle Z, is an angle whose vertex is and whose sides are radii of the circle. Angle is not a central angle of circle Z. The degree measure of an arc is the degree measure of the central angle that intercepts it. The measure of is degrees.