Arcs and Inscribed Angles

• If an angle is inscribed in a circle, then the measure of the inscribed angle equals one-half the measure of the intercepted arc or the intercepted arc is twice the measure of the inscribed angle.
• If two inscribed angles in a circle or congruent circles intercepts congruent arcs or the same arcs, then the angles are congruent.
• If an inscribed angle of a circle intercepts a semicircle, then the angle is a right angle.
• If a quadrilateral is inscribed in circle, then its opposite angles are supplementary.