Answer:
Sometimes
Explanation:
When chords intersect in a circle, the vertical angles formed intercept sometimes congruent arcs as when the two chords in a circle intersects,they form the vertex of an angle within a circle and the measure of the angle is equal to one-half the sum of the measures of the two arcs intercepted by the angle and its vertical angle. A thrifty auxiliary line is a chord connecting two of the endpoints of a chord, which forms a triangle for the vertical angles which are exterior angles of the triangle.