https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-circle-basics/v/language-and-notation-of-the-circle 2021-02-16T16:08:13Z Circles glossary Formal definition of a circle. Tangent and secant lines. Diameters and radii. major and minor arcs Sal Khan video https://cdn.kastatic.org/googleusercontent/SWae14xdpXW141daSvXpqUJZzzdAUuYNQ8-Zz-oWkTnYjVHewnV66scU53oFOzvcpEBnymxptuVTkmroZudMhhyh Circles glossary Formal definition of a circle. Tangent and secant lines. Diameters and radii. major and minor arcs https://cdn.kastatic.org/ka-youtube-converted/U2W7HPyC0cM.mp4/U2W7HPyC0cM.mp4 672 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-inscribed-angles/v/inscribed-angles-exercise-example 2022-10-07T00:00:24.225559754Z Inscribed angles Sal finds a missing inscribed angle using the inscribed angle theorem.  video https://cdn.kastatic.org/ka_thumbnails_cache/88ed8757-3b40-4b35-afd1-f5085a99a2a0_1280_720_base.png Inscribed angles Sal finds a missing inscribed angle using the inscribed angle theorem.  https://cdn.kastatic.org/ka-youtube-converted/aNi1-zeEps8.mp4/aNi1-zeEps8.mp4 80 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/xff63fac4:hs-geo-proofs-with-inscribed-shapes/v/proving-the-opposite-angles-of-inscribed-quadrilateral-are-supplementary 2022-10-07T00:00:24.225559754Z Inscribed quadrilaterals proof Sal uses the inscribed angle theorem and some algebra to prove that opposite angles of an inscribed quadrilateral are supplementary. video https://cdn.kastatic.org/ka_thumbnails_cache/db83b754-b900-4a6e-9e59-841fd678f736_1280_720_base.png Inscribed quadrilaterals proof Sal uses the inscribed angle theorem and some algebra to prove that opposite angles of an inscribed quadrilateral are supplementary. https://cdn.kastatic.org/ka-youtube-converted/LGnL17ESs3Q.mp4/LGnL17ESs3Q.mp4 236 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-inscribed-shapes/v/example-showing-supplementary-oppositie-angles-in-inscribed-quadrilateral 2022-10-07T00:00:24.225559754Z Solving inscribed quadrilaterals Example showing supplementary opposite angles in inscribed quadrilateral. video https://cdn.kastatic.org/ka_thumbnails_cache/28ae4581-65b5-4acf-8ee9-c6ef1a9f2c52_1280_720_base.png Solving inscribed quadrilaterals Example showing supplementary opposite angles in inscribed quadrilateral. https://cdn.kastatic.org/ka-youtube-converted/Y9cznjBl0Hk.mp4/Y9cznjBl0Hk.mp4 298 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-tangents/v/proving-radius-is-perpendicular-to-tangent-line 2022-10-07T00:00:24.225559754Z Proof: Radius is perpendicular to tangent line Sal proves that the radius that connects the intersection point of a tangent line with the circle is perpendicular to the tangent line. video https://cdn.kastatic.org/ka_thumbnails_cache/34b0a898-d2a2-482b-8f82-1a9a124ef762_1280_720_base.png Proof: Radius is perpendicular to tangent line Sal proves that the radius that connects the intersection point of a tangent line with the circle is perpendicular to the tangent line. https://cdn.kastatic.org/ka-youtube-converted/St3MU5i3chc.mp4/St3MU5i3chc.mp4 521 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-tangents/v/segments-tangent-to-circle-from-outside-point-congruent 2022-10-07T00:00:24.225559754Z Proof: Segments tangent to circle from outside point are congruent Sal proves that two tangent segments to a circle that are drawn from the same outside point are congruent. video https://cdn.kastatic.org/ka_thumbnails_cache/6d09b5ba-6aba-4edf-9153-b58e13735b67_1280_720_base.png Proof: Segments tangent to circle from outside point are congruent Sal proves that two tangent segments to a circle that are drawn from the same outside point are congruent. https://cdn.kastatic.org/ka-youtube-converted/pJABplruJIU.mp4/pJABplruJIU.mp4 236 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-tangents/v/tangents-of-circles-exercise-examples 2022-10-07T00:00:24.225559754Z Tangents of circles problem (example 1) Sal finds missing angles using the property that tangents are perpendicular to the radius. video https://cdn.kastatic.org/ka_thumbnails_cache/ffdd13c3-687f-4a67-9cb7-37a9c7dba0b2_1280_720_base.png Tangents of circles problem (example 1) Sal finds missing angles using the property that tangents are perpendicular to the radius. https://cdn.kastatic.org/ka-youtube-converted/8vFhNhL-zm8.mp4/8vFhNhL-zm8.mp4 277 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-tangents/v/measure-of-circumscribed-angle 2021-02-16T16:08:13Z Tangents of circles problem (example 2) Sal finds a missing angle using the property that tangents are perpendicular to the radius. Sal Khan video https://cdn.kastatic.org/googleusercontent/zIk6U1r0zx-sDeJtjdZ5HVzX8iVeQdQ9LFVT1U6hv8un3tT2iQbE2-5SDzEj90H27d8QpfOFacEKz8BjTX2iwrI Tangents of circles problem (example 2) Sal finds a missing angle using the property that tangents are perpendicular to the radius. https://cdn.kastatic.org/ka-youtube-converted/ZiqHJwzv_HI.mp4/ZiqHJwzv_HI.mp4 227 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-tangents/v/example-with-tangent-and-radius 2021-02-16T16:08:13Z Tangents of circles problem (example 3) Sal finds a missing length using the property that tangents are perpendicular to the radius. Sal Khan video https://cdn.kastatic.org/googleusercontent/PHVUS7ueki6RvdNDEZpLJMXAaaMEXjdwNAVfyHxQ5iOXhD9XeEZkdPCGehcOGnvaICWUvFBVsFnX0lxGJ4Usxmvz2w Tangents of circles problem (example 3) Sal finds a missing length using the property that tangents are perpendicular to the radius. https://cdn.kastatic.org/ka-youtube-converted/KjQ1KN5GgoE.mp4/KjQ1KN5GgoE.mp4 154 Circle, Cyclic Quadrilateral and Tangent to a Circle https://www.khanacademy.org/math/revision-up-math-class-8/xe4edb0d90ad0a387:week-2-revision-up-math-class-8/xe4edb0d90ad0a387:circle-and-cyclic-quadrilateral-revision-up-math-class-8/e/revision-circle-and-cyclic-quadrilateral-up-math-class-8 2026-04-07T23:36:17.218592739Z Revision Circle, Cyclic Quadrilateral and Tangent of a Circle Practice problems for revision of Circle, Cyclic Quadrilateral and Tangent of a Circle. Satya Swaroop exercise