https://www.khanacademy.org/math/algebra-home/alg-series-and-induction/alg-deductive-and-inductive-reasoning/v/deductive-reasoning-3 2020-07-26T05:38:46Z Using deductive reasoning Sal uses deductive reasoning to prove an algebraic identity. Sal Khan video https://cdn.kastatic.org/googleusercontent/F9L9gASbCSkqXhun0u7uqORrP-NydAdGWh3DwFrRMwnfvCIYMmCuktDj9dGKOd0VYQ2PIQ-RpZQ6gLSsXYEsRoop Using deductive reasoning Sal uses deductive reasoning to prove an algebraic identity. https://cdn.kastatic.org/ka-youtube-converted/lYLaaMObgkw.mp4/lYLaaMObgkw.mp4 251 Triangle congruency https://www.khanacademy.org/math/algebra-home/alg-series-and-induction/alg-deductive-and-inductive-reasoning/v/inductive-reasoning-2 2020-07-26T05:38:46Z Inductive reasoning Sal analyzes a solution of a mathematical problem to determine whether it uses inductive reasoning. Sal Khan video https://cdn.kastatic.org/googleusercontent/5YTqQ3TNtcJ8C6YtP_8xNcd3pKmhL9e59mPv0v_uqJ9y8eCMFaIYl3Doa-JMupk20gO88Ctfl5FK0G-7LUPCTR8I Inductive reasoning Sal analyzes a solution of a mathematical problem to determine whether it uses inductive reasoning. https://cdn.kastatic.org/ka-youtube-converted/ZSsBh4Ybbj8.mp4/ZSsBh4Ybbj8.mp4 141 Triangle congruency https://www.khanacademy.org/math/algebra-home/alg-series-and-induction/alg-deductive-and-inductive-reasoning/v/inductive-reasoning-3 2020-07-26T05:38:46Z Inductive reasoning (example 2) Sal analyzes a solution of a mathematical problem to determine whether it uses inductive reasoning. Sal Khan video https://cdn.kastatic.org/googleusercontent/WfYnMZcuoJHP7agjWCuqSlQcxo0llJ_A1Q9uagKTxEmXPSDOjTKtz6PEG7sX_cJ24rvEqrxOsAl1Euo55BmsErk Inductive reasoning (example 2) Sal analyzes a solution of a mathematical problem to determine whether it uses inductive reasoning. https://cdn.kastatic.org/ka-youtube-converted/pgfWkaySFGY.mp4/pgfWkaySFGY.mp4 183 Triangle congruency https://www.khanacademy.org/math/geometry/hs-geo-similarity/hs-geo-angle-bisector-theorem/v/angle-bisector-theorem-proof 2023-06-02T18:07:10.327662797Z Intro to angle bisector theorem The Angle Bisector Theorem states that when an angle in a triangle is split into two equal angles, it divides the opposite side into two parts. The ratio of these parts will be the same as the ratio of the sides next to the angle. Sal Khan video https://cdn.kastatic.org/googleusercontent/GyWsCYqbdq87zseUd2Adqrb92DCxxWgAL5dkofP4-PHA93Zu3VMq0rXdV_B5Uprw_XZginA4uninZfDjiZY1j2Y Intro to angle bisector theorem The Angle Bisector Theorem states that when an angle in a triangle is split into two equal angles, it divides the opposite side into two parts. The ratio of these parts will be the same as the ratio of the sides next to the angle. https://cdn.kastatic.org/ka-youtube-converted/TpIBLnRAslI.mp4/TpIBLnRAslI.mp4 515 Triangle congruency https://www.khanacademy.org/math/geometry/hs-geo-congruence/hs-geo-congruence-theorems/a/properties-of-congruence-and-equality 2024-08-02T18:09:52.444389438Z Properties of congruence and equality Learn when to apply the reflexive property, transitive, and symmetric properties in geometric proofs. Learn the relationship between equal measures and congruent figures. article https://www.khanacademy.org/math/geometry/hs-geo-congruence/hs-geo-congruence-theorems/v/equilateral-triangle-sides-and-angles-congruent 2021-02-16T16:08:14Z Proofs concerning equilateral triangles Sal proves that the angles of an equilateral triangle are all congruent (and therefore they all measure 60°), and conversely, that triangles with all congruent angles are equilateral. Sal Khan video https://cdn.kastatic.org/googleusercontent/QZ8jOQF11Eu-j3PcjFZSdaTq-lwCZ6mvoESc1Nv7ewc_iNlTMDB0BhS4Mzs2690ta8FsShYI4_IxL0-nJN-RywQJ Proofs concerning equilateral triangles Sal proves that the angles of an equilateral triangle are all congruent (and therefore they all measure 60°), and conversely, that triangles with all congruent angles are equilateral. https://cdn.kastatic.org/ka-youtube-converted/CYNUwiUzlPk.mp4/CYNUwiUzlPk.mp4 389 Triangle congruency https://www.khanacademy.org/math/geometry/hs-geo-congruence/xff63fac4:hs-geo-congruent-triangles/v/congruent-triangles-and-sss 2021-07-02T09:35:28Z Corresponding parts of congruent triangles are congruent When two triangles are congruent, we can know that all of their corresponding sides and angles are congruent too! Sal Khan video https://cdn.kastatic.org/googleusercontent/I443_grod2oGBOVt8g2JAMc_UGeH-nCQzdC1ennLrKzo0QPgyly7Ouhpcc4J3Xf7TTQ6XA5MPZemfzmJEVqnfIk5bQ Corresponding parts of congruent triangles are congruent When two triangles are congruent, we can know that all of their corresponding sides and angles are congruent too! https://cdn.kastatic.org/ka-youtube-converted/yp49bc4TT-s.mp4/yp49bc4TT-s.mp4 363 Triangle congruency https://www.khanacademy.org/math/geometry/hs-geo-congruence/xff63fac4:hs-geo-congruent-triangles/a/triangle-congruence-review 2022-09-10T02:03:40.164764806Z Triangle congruence review Review the triangle congruence criteria and use them to determine congruent triangles. article https://www.khanacademy.org/math/geometry/hs-geo-congruence/xff63fac4:hs-geo-congruent-triangles/e/congruent_triangles_1 2025-04-25T04:15:25.711210865Z Determine congruent triangles Use the triangle congruence criteria SSS, SAS, ASA, and AAS to determine that two triangles are congruent. Tomer Gal exercise https://www.khanacademy.org/math/9th-grade-math-revised-k-to-10-3-terms/x1e64c39423990571:2nd-quarter/x1e64c39423990571:triangle-conrguency/e/congruence-of-triangles 2026-04-07T23:17:37.123726494Z Congruence of Triangles Congruence of Triangles Ashish Gupta exercise https://www.khanacademy.org/math/9th-grade-math-revised-k-to-10-3-terms/x1e64c39423990571:2nd-quarter/x1e64c39423990571:triangle-conrguency/e/b9-congruent-triangles 2026-04-07T23:55:07.30621384Z Congruent triangles Congruent triangles ashish exercise https://www.khanacademy.org/math/engageny-geo/geo-1/geo-1c-transformations-apps/e/corresponding-parts-of-congruent-triangles 2026-06-15T14:50:41.678483474Z Corresponding parts of congruent triangles Lets identify corresponding parts of congruent triangles. Ashish exercise https://www.khanacademy.org/math/geometry/hs-geo-congruence/hs-geo-working-with-triangles/e/congruent_triangles_2 2026-05-06T16:50:54.748971034Z Find angles in congruent triangles Given two triangles, determine whether they are congruent and use that to find missing angle measures. Tomer Gal exercise https://www.khanacademy.org/math/geometry/hs-geo-congruence/xff63fac4:hs-geo-congruent-triangles/e/prove-triangle-congruence 2026-03-08T12:20:34.612865912Z Prove triangle congruence Given figures composed of 2 triangles, complete or find the error in the proof that the triangles are congruent. Charlotte Auen exercise