https://www.khanacademy.org/math/cc-2nd-grade-math/x3184e0ec:geometry/cc-2nd-shapes/v/shapes-and-angles 2022-10-07T04:52:10.377781811Z Shapes and angles Sal explains how to identify the angles on different shapes and then draw shapes based on their number of angles. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/bb173e90-5742-4ca6-8c43-e7830eb91954_1280_720_base.png Shapes and angles Sal explains how to identify the angles on different shapes and then draw shapes based on their number of angles. https://cdn.kastatic.org/ka-youtube-converted/FehnQ_2SgsM.mp4/FehnQ_2SgsM.mp4 208 Regular and irregular polygons https://www.khanacademy.org/math/cc-2nd-grade-math/x3184e0ec:geometry/cc-2nd-shapes/e/analyze-shapes-by-angles 2025-06-24T14:43:14.98588327Z Analyze shapes by angles Practice analyzing a shape by counting the number of angles. Kami Soltesz exercise https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-classifying-geometric-shapes/v/classifying-shapes-by-lines-and-angles 2022-10-06T09:48:27.705455518Z Classifying shapes by lines and angles Lindsay classifies a shape based on hints about its sides and angles.  video https://cdn.kastatic.org/ka_thumbnails_cache/5f4d4b9e-dc9b-411e-9941-a20626623847_1280_720_base.png Classifying shapes by lines and angles Lindsay classifies a shape based on hints about its sides and angles.  https://cdn.kastatic.org/ka-youtube-converted/xO4n3LfmVag.mp4/xO4n3LfmVag.mp4 217 Regular and irregular polygons https://www.khanacademy.org/math/cc-fifth-grade-math/properties-of-shapes/properties-shapes/e/properties-of-shapes 2026-05-01T18:40:51.669398128Z Properties of shapes Identify and compare shapes based on their attributes.  Shapes include triangle types, quadrilateral types, pentagons, and hexagons. jenoverholt exercise https://www.khanacademy.org/math/geometry-home/geometry-shapes/angles-with-polygons/v/sum-of-interior-angles-of-a-polygon 2023-04-19T21:01:17.089483175Z Sum of interior angles of a polygon To find the interior angle sum of a polygon, we can use a formula: interior angle sum = (n - 2) x 180°, where n is the number of sides. For example, a pentagon has 5 sides, so its interior angle sum is (5 - 2) x 180° = 3 x 180° = 540°. Sal Khan video https://cdn.kastatic.org/googleusercontent/Dy9dwu-r7REqsvHnPJFG9BZyZgxZhkCsmdatuLMVhinf3RDOohVKv5QYloc5nPaMFXRcHpX97XgtX1-5mr9LXQ4xFA Sum of interior angles of a polygon To find the interior angle sum of a polygon, we can use a formula: interior angle sum = (n - 2) x 180°, where n is the number of sides. For example, a pentagon has 5 sides, so its interior angle sum is (5 - 2) x 180° = 3 x 180° = 540°. https://cdn.kastatic.org/ka-youtube-converted/qG3HnRccrQU.mp4/qG3HnRccrQU.mp4 550 Regular and irregular polygons https://www.khanacademy.org/math/geometry-home/geometry-shapes/angles-with-polygons/e/angles_of_a_polygon 2026-03-24T23:41:07.080866137Z Angles of a polygon Find the sum of interior angles of different polygons. Sid Patel exercise https://www.khanacademy.org/math/geometry/hs-geo-circles/hs-geo-inscribed-polygons/v/constructing-regular-hexagon-inscribed-in-circle 2021-02-16T16:08:13Z Geometric constructions: circle-inscribed regular hexagon Sal constructs a regular hexagon that is inscribed inside a given circle using compass and straightedge. Sal Khan video https://cdn.kastatic.org/googleusercontent/pBEoaxN_Fl_bSRh2xBxhJScO42_G0DilUqJFqAKDTDWq8Nwz9ydaQ0LvFj3ANV4KRWVoBrQumxIKTGg_tNKGrqZQHw Geometric constructions: circle-inscribed regular hexagon Sal constructs a regular hexagon that is inscribed inside a given circle using compass and straightedge. https://cdn.kastatic.org/ka-youtube-converted/Yu4eqwGFJK8.mp4/Yu4eqwGFJK8.mp4 221 Regular and irregular polygons