10.4 Inscribed Angles and Polygons
What We will Learn Use inscribed angles Use inscribed polygons
Needed Vocab Inscribed angle: angle whose vertex is on a circle and whose sides contain chords Intercepted arc: arc that lies between two lines, rays, or segments Inscribed polygon: when all vertices lie on a circle Circumscribed circle: circle that contains the vertices of the polygon
Ex. 1 Using Inscribed Angles Measure of an inscribed angle is one-half the measure of its intercepted arc Find the indicated measure A. 𝑚∠𝑇 24° B. arc QR 80°
Ex. 2 Finding Measure of Intercepted Arc Find arc RS and 𝑚∠𝑆𝑇𝑅. Arc RS 62° 𝑚∠𝑆𝑇𝑅 31°
Ex. 3 Finding Angle Measure Given 𝑚∠𝐸=75°, find 𝑚∠𝐹. 75°
Ex. 4 Using Inscribed Polygons Find each value 2𝑥=90 2𝑥 2 = 90 2 𝑥=45° B. find y and z degrees Remember that opposite angles of an inscribe polygon are supplementary. Y: 60 Z: 100