10.3 Arcs and Chords If two chords are congruent, then their arcs are also congruent Inscribed quadrilaterals: the opposite angles are supplementary If a radius or diameter is perpendicular to a chord, it bisects the chord and its arc If two chords are equidistant from the center of the circle, the chords are congruent
A B C D E F If FE=BC, then arc FE = arc BC Quad. BCEF is an inscribed polygon – opposite angles are supplementary angles B + E = 180 & angles F + C = 180 Diameter AD is perpendicular to chord EC – so chord EC and arc EC are bisected
E A B C FD X *You can use the pythagorean theorem to find the radius when a chord is perpendicular to a segment from the center XE = XF so chord AB = chord CD because they are equidistant from the center You will need to draw in the radius yourself
In the circle below, diameter QS is 14 inches long and chord RT is 10 inches long. Find VU.