Section 10.3 Inscribed Angles
Inscribed Angle An angle whose vertex is on a circle and whose sides contain chords of the circle Inscribed Angle
Intercepted Arc An arc formed from an inscribed angle on a circle. Intercepted Arc
Measure of an Inscribed Angle Half the measure of its intercepted arc m ADB = ½ m AB OR m AB = 2(m ADB) 50° 100°
Examples #1-6
Theorem 10.9 If two inscribed angles of a circle intercept the same arc, then the angles are congruent. A C B D C is congruent to D It is given that m E 75 . What is the m F? 75 G E F H m F = 75
Inscribed All of the vertices of a polygon lie on a circle
Circumsribed Surrounding the figure
Theorem If a right triangle is inscribed in a circle, then the hypotenuse is the diameter. B is a right angle iff AC is the diameter A B C
Theorem A quadrilateral can be inscribed in a circle iff its opposite angles are supplementary (180°) m D + m F 180 m E + m G 180
Examples #1-6