# Congruence

## Transformations & congruence

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Congruent shapes & transformationsNon-congruent shapes & transformations
Practice
Congruence & transformationsGet 3 of 4 questions to level up!

## Triangle congruence

Learn
Congruent triangles & the SSS postulate/criterionTriangle congruence postulates/criteriaWhy SSA isn't a congruence postulate/criterionDetermining congruent trianglesTriangle congruence review
Practice
Determine congruent trianglesGet 5 of 7 questions to level up!

## Theorems concerning triangle properties

Learn
Angles in a triangle sum to 180° proofProofs concerning isosceles trianglesProofs concerning equilateral triangles

## Working with triangles

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Corresponding angles in congruent trianglesIsosceles & equilateral triangles problemsFinding angles in isosceles trianglesFinding angles in isosceles triangles (example 2)
Practice
Find angles in congruent trianglesGet 3 of 4 questions to level up!

Learn
Proof: Opposite sides of a parallelogramProof: Diagonals of a parallelogramProof: Opposite angles of a parallelogramProof: The diagonals of a kite are perpendicularProof: Rhombus diagonals are perpendicular bisectorsProof: Rhombus area

## Proofs of general theorems that use triangle congruence

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Geometry proof problem: midpointGeometry proof problem: congruent segmentsGeometry proof problem: squared circle

## Constructing bisectors of lines & angles

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Geometric constructions: perpendicular bisectorGeometric constructions: perpendicular lineGeometric constructions: angle bisector