https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-lines-line-segments-and-rays/v/lines-line-segments-and-rays 2021-06-30T20:49:37Z Lines, line segments, & rays Learn the difference between lines, line segments, and rays.  Sal Khan video https://cdn.kastatic.org/googleusercontent/-xyW_oyfXLhP58Whc8Nlu4eoLWejjfZQe7ogXZhJInSy_W8F1MMsh8OSZzLWVNmSomsC9AXh7ySDFkQEyQxzN3V4 Lines, line segments, & rays Learn the difference between lines, line segments, and rays.  https://cdn.kastatic.org/ka-youtube-converted/JcqCf762y9w.mp4/JcqCf762y9w.mp4 218 Basic Geometrical Figures https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-lines-line-segments-and-rays/e/recognizing_rays_lines_and_line_segments 2025-09-29T06:00:57.283947377Z Identify points, lines, line segments, rays, and angles Recognize points, lines, line segments, rays, and angles in geometric figures. Christopher Wobbles Seymour exercise https://www.khanacademy.org/math/class-6-ncf/x04ca845a9a148c80:lines-and-angles/x04ca845a9a148c80:types-of-angles-and-their-measures/v/acute-obtuse-and-reflex-angles 2024-05-22T06:22:00.374380016Z Acute, Obtuse and Reflex angles Learn about Acute , obtuse and reflex angles introduction Devashish Phadnis video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Acute, Obtuse and Reflex angles Learn about Acute , obtuse and reflex angles introduction https://cdn.kastatic.org/ka-youtube-converted/Jj8XhAb1-zA.mp4/Jj8XhAb1-zA.mp4 208 Basic Geometrical Figures https://www.khanacademy.org/math/class-6-ncf/x04ca845a9a148c80:lines-and-angles/x04ca845a9a148c80:types-of-angles-and-their-measures/e/types-of-angles--add-complete-and-reflex--6th 2026-04-08T01:15:04.085520103Z Types of angles Types of angles  supriya exercise https://www.khanacademy.org/math/cc-fourth-grade-math/imp-geometry-2/imp-angles-in-circles/e/types-of-angles-by-measure 2021-09-27T14:09:14.241480649Z Types of angles by measure Relate acute, obtuse, right, and straight angles to angle measures in degrees. Vicki exercise https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-angle-introduction/e/recognizing-angles 2025-05-27T12:12:40.926204724Z Recognize angles in figures Determine if angles in shapes and pictures are acute, right, or obtuse. Christopher Wobbles Seymour exercise https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-classifying-triangles/v/scalene-isosceles-equilateral-acute-right-obtuse 2023-07-24T13:48:13.07161686Z Classifying triangles The video explores how triangles are classified based on their sides and angles. It introduces the terms scalene, isosceles, and equilateral for side lengths, and acute, right, and obtuse for angles. It emphasizes that triangles can be categorized in multiple ways based on these characteristics. Sal Khan video https://cdn.kastatic.org/googleusercontent/wmcE1ICNQ2GKhtp6LRNQ8JmJgM5inf2NFAG6LfgOiBmBCSF3BfAUk2xVCtag-1XktR-C59FTrWFhayWGscT_vDQy Classifying triangles The video explores how triangles are classified based on their sides and angles. It introduces the terms scalene, isosceles, and equilateral for side lengths, and acute, right, and obtuse for angles. It emphasizes that triangles can be categorized in multiple ways based on these characteristics. https://cdn.kastatic.org/ka-youtube-converted/D5lZ3thuEeA.mp4/D5lZ3thuEeA.mp4 360 Basic Geometrical Figures https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-classifying-triangles/e/identifying-triangles-by-angles 2024-04-02T14:40:11.776966208Z Classify triangles by angles Practice identifying triangles by their angles as acute, right, or obtuse. Lindsay exercise https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-angles/v/complementary-and-supplementary-angles 2021-07-02T09:35:33Z Complementary & supplementary angles Learn about complementary and supplementary angles, as well as the definitions of adjacent and straight angles. Sal Khan video https://cdn.kastatic.org/googleusercontent/qDVRlJF769umQwhK0k5Gws2kWYPwSZplfCVSDfogMTaAgwYWW_U-6rLm70oo6ChLWcrKMyh4Np5FI6xpBfkMBSDydw Complementary & supplementary angles Learn about complementary and supplementary angles, as well as the definitions of adjacent and straight angles. https://cdn.kastatic.org/ka-youtube-converted/BTnAlNSgNsY.mp4/BTnAlNSgNsY.mp4 511 Basic Geometrical Figures https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-angles/e/complementary-and-supplementary-angles--no-visual- 2024-09-05T20:39:26.312313729Z Complementary and supplementary angles (no visual) Use complementary and supplementary angles to solve for a missing angle measure. Lindsay exercise https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-angles/e/complementary_and_supplementary_angles 2025-02-06T19:34:52.815179935Z Complementary and supplementary angles (visual) Use your knowledge about complementary and supplementary angles to find missing angles. Marcia Lee exercise https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-angles/v/angles-at-the-intersection-of-two-lines 2021-07-02T09:35:28Z Vertical angles By using our knowledge of supplementary, adjacent, and vertical angles, we can solve problems involving the intersection of two lines. Including this one! Sal Khan video https://cdn.kastatic.org/googleusercontent/vG8VY_P_fY1oMY1y1aqral5PJT2HpHQeBDB_qPJO6AdEutPu7HNvYS_ydXRTqTtJ3fzmb5rt85ux8oOh9hDwGn2_QQ Vertical angles By using our knowledge of supplementary, adjacent, and vertical angles, we can solve problems involving the intersection of two lines. Including this one! https://cdn.kastatic.org/ka-youtube-converted/_7aUxFzTG5w.mp4/_7aUxFzTG5w.mp4 439 Basic Geometrical Figures https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-angles/e/vertical_angles 2026-03-04T06:00:57.549960839Z Vertical angles Use your knowledge about vertical angles to find missing angle measures. Marcia Lee exercise https://www.khanacademy.org/math/geometry-home/geometry-angles/old-angles/v/angles-part-2 2020-06-23T07:22:43Z Angles (part 2) More on complementary and supplementary angles. Introduction to opposite angles. Sal Khan video https://cdn.kastatic.org/googleusercontent/54YyFwceiv5VKP3XzGfkyu9yv2F8uQijiFtqxBfPa-Z5av63R4UYT0sK_H9RFLxa4dfiyrrqLCeDpkygTsPzyA0zjw Angles (part 2) More on complementary and supplementary angles. Introduction to opposite angles. https://cdn.kastatic.org/ka-youtube-converted/zrqzG6xKa1A.mp4/zrqzG6xKa1A.mp4 544 Basic Geometrical Figures https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-angles/e/identifying-supplementary-complementary-vertical 2026-03-09T04:30:46.094426574Z Identifying supplementary, complementary, and vertical angles Practice telling whether two angles are supplementary, complementary, or vertical. Ben exercise https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-angles/e/angles_1 2026-03-26T21:40:53.527314638Z Finding angle measures between intersecting lines Use your knowledge about angles to find missing angle measures in various situations. David Lai exercise https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-unknown-angle-algebra/v/solving-for-unknown-angles 2021-06-30T20:49:36Z Find measure of vertical angles Given two intersecting lines and the measure of vertical angles, watch as we solve to find the measure of the remaining angles. Sal Khan video https://cdn.kastatic.org/googleusercontent/aVtKOvsU7rYr4KI8sI7tUP5co9nEpd15S4VLQ6hs_JtVsqmXaVC9aH5NkgcqZDDZY5hIQgXoHrnf_leKfDF1CXw Find measure of vertical angles Given two intersecting lines and the measure of vertical angles, watch as we solve to find the measure of the remaining angles. https://cdn.kastatic.org/ka-youtube-converted/TOobWKx1xe0.mp4/TOobWKx1xe0.mp4 180 Basic Geometrical Figures https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-unknown-angle-algebra/e/find-missing-angles 2024-10-29T20:09:48.58324612Z Finding missing angles Practice using knowledge of vertical, complementary, and supplementary angles to find a missing angle. Ben exercise https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-geometry/cc-8th-angles-between-lines/v/angles-formed-by-parallel-lines-and-transversals 2023-05-12T21:01:01.897246564Z Angles, parallel lines, & transversals Parallel lines are lines in the same plane that go in the same direction and never intersect. When a third line, called a transversal, crosses these parallel lines, it creates angles. Some angles are equal, like vertical angles (opposite angles) and corresponding angles (same position at each intersection). Sal Khan video https://cdn.kastatic.org/googleusercontent/Vz_NMEoL9pcokuLJEAFY_U-n9SIzbtc56vA_P8hGFXLXAZEIdmfteizOxfIHqBk4kThnx6aglnEoGdRMahNp4OyW3w Angles, parallel lines, & transversals Parallel lines are lines in the same plane that go in the same direction and never intersect. When a third line, called a transversal, crosses these parallel lines, it creates angles. Some angles are equal, like vertical angles (opposite angles) and corresponding angles (same position at each intersection). https://cdn.kastatic.org/ka-youtube-converted/H-E5rlpCVu4.mp4/H-E5rlpCVu4.mp4 427 Basic Geometrical Figures https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-geometry/cc-8th-angles-between-lines/v/figuring-out-angles-between-transversal-and-parallel-lines 2023-05-12T21:01:01.897246564Z Missing angles with a transversal When a third line called a transversal crosses two parallel lines, we can find the measures of angles using properties like corresponding angles, vertical angles, and supplementary angles. If we know just one of the angle measurements, these properties help us find all the missing angle measurements. Sal Khan video https://cdn.kastatic.org/googleusercontent/Jc7Hc_hUwIAHvvJpv_xjYjVmNGH5TEE0q90O7tSCCMK6BQ1fOzUe2zl-KCs-2bpIZZ-87m_tAVueoL37Wiy8QB5SOw Missing angles with a transversal When a third line called a transversal crosses two parallel lines, we can find the measures of angles using properties like corresponding angles, vertical angles, and supplementary angles. If we know just one of the angle measurements, these properties help us find all the missing angle measurements. https://cdn.kastatic.org/ka-youtube-converted/2WjGD3LZEWo.mp4/2WjGD3LZEWo.mp4 136 Basic Geometrical Figures https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-geometry/cc-8th-angles-between-lines/e/parallel_lines_1 2026-03-24T23:41:07.080866137Z Angle relationships with parallel lines Find missing angles given two parallel lines and a transversal. Marcia Lee exercise