https://www.khanacademy.org/math/revision-term-1-mh-math-class-8/x0c43044bb5624863:week-2/x0c43044bb5624863:altitudes-and-median-of-triangles/v/what-are-altitudes-of-triangle 2024-05-28T09:47:20.658952794Z What are altitudes of triangle In this video we discuss what is an altitude of a triangle and how we can draw/identitfy different altitudes of the triangle Devashish Phadnis video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw What are altitudes of triangle In this video we discuss what is an altitude of a triangle and how we can draw/identitfy different altitudes of the triangle https://cdn.kastatic.org/ka-youtube-converted/X2v5aCK5ZoI.mp4/X2v5aCK5ZoI.mp4 206 Properties of Triangles https://www.khanacademy.org/districts-courses/geometry-scps-pilot-textbook/x398e4b4a0a333d18:properties-and-attributes-of-triangles/x398e4b4a0a333d18:medians-and-altitudes-of-triangles/v/intro-to-medians-of-a-triangle-class-7-india-math-khan-academy 2021-07-02T09:35:35Z Intro to medians of a triangle Let's get introduced to medians of a triangle and learn what centroids are. Aanand Srinivas video https://cdn.kastatic.org/googleusercontent/t7OPUsgVEIuYj41K54WrfklJHYd53UanJSJy1-buyZqs7XSIOtz2ZajmyOuocKoTtELjjxKf0bqFxqSomwA-11ZNuA Intro to medians of a triangle Let's get introduced to medians of a triangle and learn what centroids are. https://cdn.kastatic.org/ka-youtube-converted/cr92Xwb4CoA.mp4/cr92Xwb4CoA.mp4 328 Properties of Triangles https://www.khanacademy.org/districts-courses/geometry-scps-pilot-textbook/x398e4b4a0a333d18:properties-and-attributes-of-triangles/x398e4b4a0a333d18:medians-and-altitudes-of-triangles/e/identify-median-and-altitude 2026-04-08T01:15:04.085520103Z Identify medians and altitudes Practice identifying medians and altitudes in triangles. Ashish exercise https://www.khanacademy.org/math/class-7-ncf/x063f95a40c290960:a-tale-of-three-intersecting-lines/x063f95a40c290960:properties-of-triangles-part-2/v/exterior-angle-property-of-a-triangle 2024-05-28T09:47:20.658952794Z Exterior angle property of a triangle We look at the exterior angle property of the triangle and a quick problem on how to apply it. Devashish Phadnis video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Exterior angle property of a triangle We look at the exterior angle property of the triangle and a quick problem on how to apply it. https://cdn.kastatic.org/ka-youtube-converted/RFKQq6yvRSc.mp4/RFKQq6yvRSc.mp4 263 Properties of Triangles https://www.khanacademy.org/math/class-7-ncf/x063f95a40c290960:a-tale-of-three-intersecting-lines/x063f95a40c290960:properties-of-triangles-part-2/e/understand-exterior-angle-property 2026-04-07T23:17:37.123726494Z Understand triangle exterior angle property Let's learn where and how the triangle exterior angle property can be applied. Aanand exercise https://www.khanacademy.org/districts-courses/geometry-scps-pilot-textbook/x398e4b4a0a333d18:triangle-congruence/x398e4b4a0a333d18:angle-relationships-in-triangles/e/exterior-angle-property-problems 2026-04-07T23:36:17.218592739Z Triangle exterior angle property problems Let's use the exterior angle property to find missing angles. Aanand exercise https://www.khanacademy.org/math/geometry/hs-geo-congruence/hs-geo-congruence-theorems/v/proof-sum-of-measures-of-angles-in-a-triangle-are-180 2023-05-12T21:01:01.897246564Z Angles in a triangle sum to 180° proof The sum of the interior angle measures of a triangle always adds up to 180°. We can draw a line parallel to the base of any triangle through its third vertex. Then we use transversals, vertical angles, and corresponding angles to rearrange those angle measures into a straight line, proving that they must add up to 180°. Sal Khan video https://cdn.kastatic.org/googleusercontent/-_9m7sXFJ_DZGRlkqOTzZjy4vuXCY0hC1HrMevIJscQ5fyFoU8mekOV5C99_DXZ89kc-lHRN1rhn4WhPlCY4svU Angles in a triangle sum to 180° proof The sum of the interior angle measures of a triangle always adds up to 180°. We can draw a line parallel to the base of any triangle through its third vertex. Then we use transversals, vertical angles, and corresponding angles to rearrange those angle measures into a straight line, proving that they must add up to 180°. https://cdn.kastatic.org/ka-youtube-converted/6s1CI3uuhko.mp4/6s1CI3uuhko.mp4 268 Properties of Triangles https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-geometry/cc-8th-triangle-angles/e/triangle_angles_1 2026-03-31T08:44:48.259988263Z Find angles in triangles Find missing angle measures in triangles using the properties of general triangles, isosceles triangles, and equilateral triangles. Tomer Gal exercise https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-constructing-geometric-shapes/v/triangle-inqequality-theorem 2021-07-02T09:35:27Z Triangle inequality theorem Intuition behind the triangle inequality theorem Sal Khan video https://cdn.kastatic.org/googleusercontent/HVpDfgDPIvUqFIbXtljJrLuUlHyeiWRomrkj6JeKGb5TPNgSbX0u_nX0Aj7RYaPpLreDkNourl80NDiBdD8tPeQ Triangle inequality theorem Intuition behind the triangle inequality theorem https://cdn.kastatic.org/ka-youtube-converted/KlKYvbigBqs.mp4/KlKYvbigBqs.mp4 352 Properties of Triangles https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-constructing-geometric-shapes/e/triangle_inequality_theorem 2025-10-14T14:00:50.911555133Z Triangle side length rules Given the lengths of two sides of a triangle, what can we say about the third side? Igor Terzic exercise