Inscribed Angle in a Circle Proof Small 254×320 Medium 509×640 Large 814×1024 Download Tiff Original 1907×2400 | (247.9 KB) Description Illustration of a circle with an inscribed angle that can be used to prove that "An inscribed angle is measured by one half of its intercepted arc." In this case, one side of angle ABC passes through the center of the circle. Keywords angle passing through center, angles, circle, circles, diameter, geometry, inscribed angle Galleries Geometric Theorems and Proofs Source: C.A. Hart, Daniel D. Feldman Plane and Solid Geometry (New York, NY: American Book Company, 1911) Courtesy the private collection of Roy Winkelman