https://www.khanacademy.org/math/geometry-home/geometry-miscellaneous/geometry-worked-examples/v/ca-geometry-basic-trigonometry 2020-06-23T07:22:43Z CA Geometry: Basic trigonometry 61-65, basic trigonometry Sal Khan video https://cdn.kastatic.org/googleusercontent/vku8dswiXFyAlagmoXvJob2_ynqzV1rtqGHHR9xhN-g_P8cuwC13IRMK4lYS6FeBS8dqg34Ukjlk8b9plCvZSnQ CA Geometry: Basic trigonometry 61-65, basic trigonometry https://cdn.kastatic.org/ka-youtube-converted/MyvRxKM0xns.mp4/MyvRxKM0xns.mp4 664 Trigonometry https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:trig/x2ec2f6f830c9fb89:unit-circle/v/unit-circle-definition-of-trig-functions-1 2021-06-30T17:32:39Z Unit circle Learn how to use the unit circle to define sine, cosine, and tangent for all real numbers. Sal Khan video https://cdn.kastatic.org/googleusercontent/4va3CHgzmCX8w1NMhs0LlyYxLMiXHDwZ-dDm8quQ0X5OKdz1Yj1KGmmUatzGzQcx5s4jzRHet0bYdh0NK-KNxB3iTw Unit circle Learn how to use the unit circle to define sine, cosine, and tangent for all real numbers. https://cdn.kastatic.org/ka-youtube-converted/1m9p9iubMLU.mp4/1m9p9iubMLU.mp4 544 Trigonometry https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:trig/x2ec2f6f830c9fb89:unit-circle/e/unit-circle 2026-04-08T00:54:09.631945657Z Unit circle Practice your understanding of the unit circle definition of sine and cosine. Tomer Gal exercise https://www.khanacademy.org/math/geometry-home/right-triangles-topic/intro-to-the-trig-ratios-geo/v/basic-trigonometry 2023-04-19T21:28:53.788177796Z Intro to the trigonometric ratios Sin, cos, and tan are trigonometric ratios that relate the angles and sides of right triangles. Sin is the ratio of the opposite side to the hypotenuse, cos is the ratio of the adjacent side to the hypotenuse, and tan is the ratio of the opposite side to the adjacent side. They are often written as sin(x), cos(x), and tan(x), where x is an angle in radians or degrees. Sal Khan video https://cdn.kastatic.org/googleusercontent/92f-z9P3xlQjRzRxw0jbZbOpAzwmjBTqS0jsZc35x2__HYRgkdQOu9L4be8LG41cffV9nRfKOwGzLFG8nw-Oi_en Intro to the trigonometric ratios Sin, cos, and tan are trigonometric ratios that relate the angles and sides of right triangles. Sin is the ratio of the opposite side to the hypotenuse, cos is the ratio of the adjacent side to the hypotenuse, and tan is the ratio of the opposite side to the adjacent side. They are often written as sin(x), cos(x), and tan(x), where x is an angle in radians or degrees. https://cdn.kastatic.org/ka-youtube-converted/Jsiy4TxgIME.mp4/Jsiy4TxgIME.mp4 557 Trigonometry https://www.khanacademy.org/math/trigonometry/trigonometry-right-triangles/sine-and-cosine-of-complementary-angles/a/trig-ratios-of-special-triangles 2025-03-12T14:20:10.072734823Z Trig ratios of special triangles Learn to find the sine, cosine, and tangent of 45-45-90 triangles and also 30-60-90 triangles. article https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-complementary-angles/v/showing-relationship-between-cosine-and-sine-of-complements 2020-11-15T14:51:33Z Sine & cosine of complementary angles Sal shows that the sine of any angle is equal to the cosine of its complementary angle. Sal Khan video https://cdn.kastatic.org/googleusercontent/GPRyLoH5PFUsrCTf3BYhDIC8ili2yQe4f_RYH-3FMWaH0pVLR4KPuaxPuDIFpCEsOCXESJoe8VfobT-3LiLWZ03Ecg Sine & cosine of complementary angles Sal shows that the sine of any angle is equal to the cosine of its complementary angle. https://cdn.kastatic.org/ka-youtube-converted/BLQNL_UGONg.mp4/BLQNL_UGONg.mp4 255 Trigonometry https://www.khanacademy.org/math/10-mr-foundation/x09747e87495927f2:geometry/x09747e87495927f2:trigonometric-ratios-of-complementary-angles/e/evaluating-trigonometric-ratios-of-complementary-angles 2025-12-30T07:05:15.972746521Z Evaluating trigonometric ratios of complementary angles Let's evaluate trigonometric ratios of complementary angles. ashish exercise https://www.khanacademy.org/math/trigonometry/trigonometry-right-triangles/reciprocal-trig-ratios/a/sine-and-cosine-are-cofunctions 2021-07-03T04:45:03Z Sine & cosine of complementary angles Learn about the relationship between the sine & cosine of complementary angles, which are angles who together sum up to 90°. article https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-complementary-angles/v/how-much-of-a-pyramid-is-submerged 2024-01-03T21:23:26.170694576Z Trig word problem: complementary angles Sal solves a problem about a submerged pyramid by finding congruent angles in the diagram and using the fact that the cosine of a given angle is always the same, no matter how large the triangle it appears in. Sal Khan video https://cdn.kastatic.org/googleusercontent/V8vWIkXXaVSc_TpmXLbHkhgSpf4wL0X0q3AohshE3sWKa2HD3g3jVyT542Ixl1vet9dA1bvADir_vP6jfp8ecaZGdg Trig word problem: complementary angles Sal solves a problem about a submerged pyramid by finding congruent angles in the diagram and using the fact that the cosine of a given angle is always the same, no matter how large the triangle it appears in. https://cdn.kastatic.org/ka-youtube-converted/Z5EnuVJawmY.mp4/Z5EnuVJawmY.mp4 344 Trigonometry https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-complementary-angles/v/sine-and-cosine-of-complements-example 2020-11-15T14:51:34Z Using complementary angles Sal solved the following problem: Given that cos(58°)=0.53, find sin(32°). Sal Khan video https://cdn.kastatic.org/googleusercontent/zzanWAOY9ojp0mfhBLPWlcFEgMbyEOUSZOOrwcdzxMeZjp5CCDM_pGgwSu7uOPZmCvd8b9mnxKc52uEjHEJSdOA Using complementary angles Sal solved the following problem: Given that cos(58°)=0.53, find sin(32°). https://cdn.kastatic.org/ka-youtube-converted/yiH6GoscimY.mp4/yiH6GoscimY.mp4 245 Trigonometry https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-trig-ratios-intro/v/basic-trigonometry-ii 2021-06-30T17:32:36Z Trigonometric ratios in right triangles Sal shows a few examples where he starts with the two legs of a right triangle and he finds the trig ratios of one of the acute angles. Sal Khan video https://cdn.kastatic.org/googleusercontent/cwpGy84NzSmhKdw05CgXGtrk00QP2OcirhTztXczYdrISg6awjAEHFhgQLuF8VUYPmXsM-LOJBMBVSmZ3yP555zf Trigonometric ratios in right triangles Sal shows a few examples where he starts with the two legs of a right triangle and he finds the trig ratios of one of the acute angles. https://cdn.kastatic.org/ka-youtube-converted/G-T_6hCdMQc.mp4/G-T_6hCdMQc.mp4 731 Trigonometry https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-trig-ratios-intro/a/finding-trig-ratios-in-right-triangles 2022-09-10T02:03:40.164764806Z Trigonometric ratios in right triangles Learn how to find the sine, cosine, and tangent of angles in right triangles. article https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-trig-ratios-intro/e/trigonometry_1 2026-04-01T11:24:50.133517701Z Trigonometric ratios in right triangles Given the side lengths of a right triangle, find the sine, cosine, or tangent of one of the acute angles. Tomer Gal exercise https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:trig/x2ec2f6f830c9fb89:unit-circle/v/matching-ratios-trig-functions 2021-06-30T17:32:35Z The trig functions & right triangle trig ratios Sal shows how, for acute angles, the two different definitions of the trigonometric values (SOH CAH TOA and the unit circle definition) result in the same values. Sal Khan video https://cdn.kastatic.org/googleusercontent/c0UdQAIw0Z9Y4urOKTHbmOHKFTJHkq7hOgH3dDSYlUf2TnGutCehCIcgi4p5iBxnlOEdinR2IhzIwUgqGyl3NnBy The trig functions & right triangle trig ratios Sal shows how, for acute angles, the two different definitions of the trigonometric values (SOH CAH TOA and the unit circle definition) result in the same values. https://cdn.kastatic.org/ka-youtube-converted/WffVdYETdng.mp4/WffVdYETdng.mp4 417 Trigonometry https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-solve-for-a-side/v/example-trig-to-solve-the-sides-and-angles-of-a-right-triangle 2021-06-30T17:32:38Z Solving for a side in right triangles with trigonometry Sal is given a right triangle with an acute angle of 65° and a leg of 5 units, and he uses trigonometry to find the two missing sides. Sal Khan video https://cdn.kastatic.org/googleusercontent/X0ECxxkRbmZu7H78vm4EbH8BRKYqPBGlzkuAdFqDsmG5d33yLEW3qY54S02C0-YF6OUMI-SPnXfHJYAyuzICHfCYJQ Solving for a side in right triangles with trigonometry Sal is given a right triangle with an acute angle of 65° and a leg of 5 units, and he uses trigonometry to find the two missing sides. https://cdn.kastatic.org/ka-youtube-converted/l5VbdqRjTXc.mp4/l5VbdqRjTXc.mp4 424 Trigonometry https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-solve-for-a-side/a/unknown-side-in-right-triangle-w-trig 2025-02-11T16:42:34.189704851Z Solving for a side in right triangles with trigonometry Learn how to use trig functions to find an unknown side length in a right triangle. article https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-solve-for-a-side/e/trigonometry_2 2025-03-09T12:38:48.303569754Z Solve for a side in right triangles Given one side length and an acute angle in a right triangle, find another side using trigonometry. Tomer Gal exercise https://www.khanacademy.org/math/trigonometry/trigonometry-right-triangles/reciprocal-trig-ratios/v/example-using-trig-to-solve-for-missing-information 2021-07-03T04:45:05Z Using reciprocal trig ratios Sal is given two sides in a right triangle and the cotangent of one of the angles, and he uses this information to find the missing side. Sal Khan video https://cdn.kastatic.org/googleusercontent/AmKt-bxoFj2Uh1jAQYZTmdnTcjoTJQPJM9kEBgD49NkS09EedRi7-guKBvGt5yQNG4bBTPpyWijUmFjbJBTs1vWU Using reciprocal trig ratios Sal is given two sides in a right triangle and the cotangent of one of the angles, and he uses this information to find the missing side. https://cdn.kastatic.org/ka-youtube-converted/rufFQZDDXCE.mp4/rufFQZDDXCE.mp4 372 Trigonometry https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-solve-for-an-angle/a/inverse-trig-functions-intro 2026-03-05T14:30:38.694195715Z Intro to inverse trig functions Learn about arcsine, arccosine, and arctangent, and how they can be used to solve for a missing angle in right triangles. article https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-solve-for-an-angle/e/solve-for-an-angle-in-a-right-triangle 2024-09-04T17:59:01.633715485Z Solve for an angle in right triangles Given two sides in a right triangle, find one of the acute angles using trigonometry. Tomer Gal exercise https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-modeling-with-right-triangles/v/angle-to-aim-to-get-alien 2021-06-30T17:32:40Z Right triangle word problem Sal solves a modeling problem where he finds the necessary angle to shoot at a vicious alien. Sal Khan video https://cdn.kastatic.org/googleusercontent/dlKu1szoXgEqwAoKxoMQLwa9LQVPo-o5Xt6xJ7m4NixSAhQDy0ixvWC3z9NTDTrLNi4qYlA-wQGTGhmRy0ab_ypT Right triangle word problem Sal solves a modeling problem where he finds the necessary angle to shoot at a vicious alien. https://cdn.kastatic.org/ka-youtube-converted/aHzd-u35LuA.mp4/aHzd-u35LuA.mp4 275 Trigonometry https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-modeling-with-right-triangles/e/applying-right-triangles 2026-05-06T06:30:43.913440672Z Right triangle trigonometry word problems Solve word problems by modeling real-world (and not-so-real) situations as right triangles and using trigonometry. Tomer Gal exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:trig/x9e81a4f98389efdf:solving-general-triangles/e/law-of-sines-and-cosines-word-problems 2026-03-26T05:20:35.16058035Z General triangle word problems Solve word problems that involve general (non-right) triangles using the law of sines and law of cosines. Cameron Christensen exercise https://www.khanacademy.org/math/cambridge-o-level-mathematics-4024/x3f4c73d082a798eb:trigonometry/x3f4c73d082a798eb:angle-of-elevation-and-depression/v/intro-to-heights-distances 2026-03-10T04:30:37.966653692Z Intro to heights & distances Created by Khan Academy Khan Academy Pakistan video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Intro to heights & distances Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/34029t0DRRU.mp4/34029t0DRRU.mp4 767 Trigonometry https://www.khanacademy.org/math/geometry-home/geometry-miscellaneous/geometry-worked-examples/v/ca-geometry-more-trig 2020-06-23T07:22:43Z CA Geometry: More trig 66-70, more trigonometry Sal Khan video https://cdn.kastatic.org/googleusercontent/1zJwAlTT7pgEySh4heDNmZtnDlus8zMhRW4L59wvCvtt83rkf0FXUWGKdRjy8jb27ZUuQ-Xs7FkBBhkCOOprLB8hHw CA Geometry: More trig 66-70, more trigonometry https://cdn.kastatic.org/ka-youtube-converted/8YBQQ0GeusM.mp4/8YBQQ0GeusM.mp4 741 Trigonometry