G.GSR.6.1
Explain that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.
Khan Academy ResourcesTriangle 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 trianglesDilations: scale factorDilate trianglesProve triangle propertiesProve parallelogram propertiesSimilarity & transformationsProve triangle congruenceDetermining congruent trianglesGeometry proof problem: congruent segmentsGeometry proof problem: midpointFinding angles in isosceles triangles (example 2)Finding angles in isosceles trianglesCorresponding angles in congruent trianglesSolving 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 circleDilating shapes: expandingDilations: scale factorDilating shapes: shrinking by 1/2Calculating angle measures to verify congruenceGeometry word problem: Earth & Moon radiiGeometry word problem: a perfect pool shotProving triangle congruenceGeometry word problem: the golden ratioSimilar shapes & transformations

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