M.GHS.18

Use congruence and similarity criteria for triangles to solve problems and to prove relationships in geometric figures.

Khan Academy Resources
Triangle similarity reviewTriangle congruence reviewDetermine congruent trianglesFind angles in congruent trianglesSolve triangles: angle bisector theoremDetermine similar triangles: AnglesSpecial right trianglesDetermine similar triangles: SSSSolve similar triangles (basic)Solve similar triangles (advanced)Use similar trianglesProve triangle similarityJustify constructionsUse ratios in right trianglesFind angles in isosceles trianglesProve triangle propertiesProve parallelogram propertiesProve triangle congruenceDetermining congruent trianglesGeometry proof problem: congruent segmentsGeometry proof problem: midpointIsosceles & equilateral triangles problemsFinding angles in isosceles triangles (example 2)Finding angles in isosceles trianglesCorresponding angles in congruent trianglesTriangle similarity postulates/criteriaSolving similar trianglesDetermining similar trianglesSolving similar triangles: same side plays different rolesChallenging similarity problemUsing similar & congruent triangles30-60-90 triangle example problemUsing the angle bisector theoremGeometry proof problem: squared circleProving the SAS triangle congruence criterion using transformationsProving the SSS triangle congruence criterion using transformationsCalculating angle measures to verify congruenceGeometry word problem: Earth & Moon radiiGeometry word problem: a perfect pool shotProving the ASA and AAS triangle congruence criteria using transformationsProving triangle congruenceGeometry word problem: the golden ratio
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