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Unit: Congruence

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Possible mastery points

Transformations & congruence

Learn
Getting ready for congruence
(Opens a modal)
Congruent shapes & transformations
(Opens a modal)
Non-congruent shapes & transformations
(Opens a modal)
Segment congruence equivalent to having same length
(Opens a modal)
Angle congruence equivalent to having same measure
(Opens a modal)
Practice
Congruence & transformationsGet 3 of 4 questions to level up!

Triangle congruence from transformations

Learn
Proving the SSS triangle congruence criterion using transformations
(Opens a modal)
Proving the SAS triangle congruence criterion using transformations
(Opens a modal)
Proving the ASA and AAS triangle congruence criteria using transformations
(Opens a modal)
Why SSA isn't a congruence postulate/criterion
(Opens a modal)
Practice
Justify triangle congruenceGet 3 of 4 questions to level up!

Congruent triangles

Learn
Triangle congruence postulates/criteria
(Opens a modal)
Determining congruent triangles
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Calculating angle measures to verify congruence
(Opens a modal)
Corresponding parts of congruent triangles are congruent
(Opens a modal)
Proving triangle congruence
(Opens a modal)
Triangle congruence review
(Opens a modal)
Practice
Determine congruent trianglesGet 5 of 7 questions to level up!
Prove triangle congruenceGet 3 of 4 questions to level up!

Quiz 1

Level up on the above skills and collect up to 400 Mastery points

Theorems concerning triangle properties

Learn
Properties of congruence and equality
(Opens a modal)
Angles in a triangle sum to 180° proof
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Proofs concerning isosceles triangles
(Opens a modal)
Proofs concerning equilateral triangles
(Opens a modal)
Triangle exterior angle example
(Opens a modal)
Practice
Prove triangle propertiesGet 3 of 4 questions to level up!

Working with triangles

Learn
Corresponding angles in congruent triangles
(Opens a modal)
Isosceles & equilateral triangles problems
(Opens a modal)
Finding angles in isosceles triangles
(Opens a modal)
Finding angles in isosceles triangles (example 2)
(Opens a modal)
Practice
Find angles in congruent trianglesGet 3 of 4 questions to level up!
Find angles in isosceles trianglesGet 3 of 4 questions to level up!

Quiz 2

Level up on the above skills and collect up to 300 Mastery points

Theorems concerning quadrilateral properties

Learn
Proof: Opposite sides of a parallelogram
(Opens a modal)
Proof: Diagonals of a parallelogram
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Proof: Opposite angles of a parallelogram
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Proof: The diagonals of a kite are perpendicular
(Opens a modal)
Proof: Rhombus diagonals are perpendicular bisectors
(Opens a modal)
Proof: Rhombus area
(Opens a modal)
Practice
Prove parallelogram propertiesGet 5 of 7 questions to level up!

Proofs of general theorems

Learn
Geometry proof problem: midpoint
(Opens a modal)
Geometry proof problem: congruent segments
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Geometry proof problem: squared circle
(Opens a modal)

Constructing lines & angles

Learn
Geometric constructions: congruent angles
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Geometric constructions: parallel line
(Opens a modal)
Geometric constructions: perpendicular bisector
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Geometric constructions: perpendicular line through a point on the line
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Geometric constructions: perpendicular line through a point not on the line
(Opens a modal)
Geometric constructions: angle bisector
(Opens a modal)
Practice
Justify constructionsGet 3 of 4 questions to level up!

Quiz 3

Level up on the above skills and collect up to 200 Mastery points
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Unit test

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About this unit

Learn what it means for two figures to be congruent, and how to determine whether two figures are congruent or not. Use this immensely important concept to prove various geometric theorems about triangles and parallelograms.