Circle x is shown. 2 chords intersect at a point to form arcs a and b. arc a is intercepted by angle 1. arc b is intercepted by angle 2. arcs d and c are the other 2 arcs. which equation can be used to solve for m∠1? m∠1 = one-half(a – b) m∠1 = one-half(a + b) m∠1 = one-half(c – d) m∠1 = one-half(c + d)