https://www.khanacademy.org/math/geometry/hs-geo-analytic-geometry/hs-geo-parallel-perpendicular-lines/v/parallel-and-perpendicular-lines-intro 2021-06-30T20:49:34Z Parallel & perpendicular lines intro Parallel lines never intersect, and perpendicular lines intersect at a 90 degree angle. Learn how to identify parallel and perpendicular lines. Sal Khan video https://cdn.kastatic.org/googleusercontent/CRTGzDu0cHddrkhiOFmwrkf50_2Kd0kMEh9xECcGSiBHgA0RMavpcbIUUkOTzPKm6jUKCuCa1fUipy280HvNtevJEQ Parallel & perpendicular lines intro Parallel lines never intersect, and perpendicular lines intersect at a 90 degree angle. Learn how to identify parallel and perpendicular lines. https://cdn.kastatic.org/ka-youtube-converted/V0xounKGEXs.mp4/V0xounKGEXs.mp4 128 Parallel and perpendicular lines https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-geometry/cc-8th-angles-between-lines/v/identifying-parallel-and-perpendicular-lines 2023-05-12T21:01:01.897246564Z Parallel & perpendicular lines Parallel lines are lines that never intersect, and they form the same angle when they cross another line. Perpendicular lines intersect at a 90-degree angle, forming a square corner. We can identify these lines using angles and symbols in diagrams. Sal Khan video https://cdn.kastatic.org/googleusercontent/PcuXlEbaHxzChubchbUd0bdEVQROnswU9iN3kZmGye3iZfHzIf_3SYhVwwxrzD8EN-ip61hIT490bsiCUZhIeiPq2w Parallel & perpendicular lines Parallel lines are lines that never intersect, and they form the same angle when they cross another line. Perpendicular lines intersect at a 90-degree angle, forming a square corner. We can identify these lines using angles and symbols in diagrams. https://cdn.kastatic.org/ka-youtube-converted/aq_XL6FrmGs.mp4/aq_XL6FrmGs.mp4 215 Parallel and perpendicular lines https://www.khanacademy.org/math/geometry/hs-geo-congruence/hs-geo-bisectors/v/constructing-parallel-lines 2022-09-10T02:03:40.164764806Z Geometric constructions: parallel line We can parallel lines with compass and straightedge by creating a pair of congruent corresponding angles on a transversal. video https://cdn.kastatic.org/ka_thumbnails_cache/a98a299d-ab26-4081-9f38-30b6631e87a8_1280_720_base.png Geometric constructions: parallel line We can parallel lines with compass and straightedge by creating a pair of congruent corresponding angles on a transversal. https://cdn.kastatic.org/ka-youtube-converted/BHLre3UiIho.mp4/BHLre3UiIho.mp4 123 Parallel and perpendicular lines https://www.khanacademy.org/math/geometry/hs-geo-congruence/hs-geo-bisectors/v/constructing-a-perpendicular-line-using-a-compass-and-straightedge 2021-02-16T16:08:14Z Geometric constructions: perpendicular line through a point on the line Sal constructs a line perpendicular to a given line through a point on the line using compass and straightedge. Sal Khan video https://cdn.kastatic.org/googleusercontent/NgTArIZqt6AglZ5SQuuNIwywyAkEg_zZJqGW0Xai67WihDqRYr00cfCae-2SOniO0jK4s-vt5hZ6O0Zg66frCEsD Geometric constructions: perpendicular line through a point on the line Sal constructs a line perpendicular to a given line through a point on the line using compass and straightedge. https://cdn.kastatic.org/ka-youtube-converted/nM-O8llUdwg.mp4/nM-O8llUdwg.mp4 72 Parallel and perpendicular lines https://www.khanacademy.org/math/geometry/hs-geo-congruence/hs-geo-bisectors/v/geometric-constructions-perpendicular-line-through-a-point-not-on-the-line 2021-02-07T17:14:00Z Geometric constructions: perpendicular line through a point not on the line We can construct a perpendicular line through a point off the line. The lines must be perpendicular because a rhombus's diagonals are perpendicular. video https://cdn.kastatic.org/googleusercontent/mKYXjju71wAr3Vy6ys_yUJ5S2oSmi__H48LacOKR1o_m-z3slNSRZnh3wgHGwIef_hRrwBRCsCnImgupvwZPCUYOrQ Geometric constructions: perpendicular line through a point not on the line We can construct a perpendicular line through a point off the line. The lines must be perpendicular because a rhombus's diagonals are perpendicular. https://cdn.kastatic.org/ka-youtube-converted/-ltjjKgGY7o.mp4/-ltjjKgGY7o.mp4 162 Parallel and perpendicular lines https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-parallel-and-perpendicular/v/drawing-lines-exercise-example 2021-05-07T00:21:36Z Drawing parallel line segments Sal draws parallel line segments with given points. Sal Khan video https://cdn.kastatic.org/googleusercontent/He2vwSkzdRzMhwRTz559EWXx-ahQeUuI1rdtAMzUwmRmcmvA-a6CC38kor1edB5DDkSbEgBbivcFo2vq9fbRnALb Drawing parallel line segments Sal draws parallel line segments with given points. https://cdn.kastatic.org/ka-youtube-converted/DkZnevdbf0A.mp4/DkZnevdbf0A.mp4 115 Parallel and perpendicular lines https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-parallel-and-perpendicular/e/drawing-parallel-and-perpendicular-lines 2026-03-25T20:00:51.494577527Z Draw parallel and perpendicular lines Practice drawing parallel and perpendicular lines, line segments, and ray. Lindsay exercise https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-parallel-and-perpendicular/a/parallel-perpendicular-review 2021-05-07T00:21:38Z Parallel and perpendicular lines review Review the basics of parallel and perpendicular lines.  Identify and draw parallel and perpendicular lines in some practice problems.   article 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 Parallel and perpendicular lines 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 https://www.khanacademy.org/math/revision-term-1-mh-math-class-8/x0c43044bb5624863:week-1/x0c43044bb5624863:parallel-lines-and-transversal/e/parallel-and-perpendicular-lines-9-b 2026-04-07T23:17:37.123726494Z Angles made by a transversal - Names Parallel and Perpendicular lines ashish exercise 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 Parallel and perpendicular lines https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-geometry/cc-8th-angles-between-lines/v/using-algebra-to-find-measures-of-angles-formed-from-transversal 2025-06-10T12:18:12.264638758Z Measures of angles formed by a transversal When parallel lines are crossed by another line called a transversal, special angles are formed. We can find the measures of these angles using algebra and the relationships between the angles, like congruent angles and supplementary angles. Once we solve for the variable, we use that value to figure out the angle measures. Sal Khan video https://cdn.kastatic.org/googleusercontent/jH5ENXnD6D-PN3MBbpChj1DItsL6-IBBlBy4CSWjNhZisvLGEEEuEoyVVhW6tRAfsndWS8O7Q7v4u9lIu_ugTO9D Measures of angles formed by a transversal When parallel lines are crossed by another line called a transversal, special angles are formed. We can find the measures of these angles using algebra and the relationships between the angles, like congruent angles and supplementary angles. Once we solve for the variable, we use that value to figure out the angle measures. https://cdn.kastatic.org/ka-youtube-converted/Ld7Vxb5XV6A.mp4/Ld7Vxb5XV6A.mp4 281 Parallel and perpendicular lines https://www.khanacademy.org/math/class-7-ncf/x063f95a40c290960:parallel-and-intersecting-lines/x063f95a40c290960:parallel-lines-and-transversal/e/perpendicular-and-parallel-lines-9-c 2026-04-07T22:59:30.107127435Z Finding angles made by a transversal Perpendicular and parallel lines ashish exercise https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-geometry/cc-8th-angles-between-lines/e/parallel_lines_2 2026-03-31T21:47:15.031073863Z Equation practice with angles Solve for angle measures on angles formed by parallel lines and a transversal, where the angle measures are given as linear expressions. Matt Wahl exercise https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:lines-and-angles/x06d55bfa213a79fd:lines-and-transversal/e/transversal-9th 2026-05-27T07:20:36.932519492Z Solving angles formed by parallel lines and transversal Solving angles formed by parallel lines and transversal supriya exercise