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Geometry · Lessons

Geometry lessons

18 sections · 50 skills · work through the full outline skill by skill — read the long-form lesson or flip through the slide-style version.
Long-form lessonsSlide-style lessons

Geometry

Practice 50 skills across this outline.

Recommended next
All Circles Are Similar
Trigonometry in General Triangles
Long-form lesson
Weighting distribution
19 categories
Trigonometry in General Triangles
6%
Modeling with Geometry
6%
Theorems About Circles
6%
Coordinate Geometry Proofs
6%
Geometry & Conic Sections
6%
Congruence & Rigid Motions
6%

Skills

The comprehensive taxonomy of geometry — drill into a card to work its skills.

Trigonometry in General Triangles

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
All Circles Are SimilarRecommended
Long-form
2
Applying Laws of Sines and CosinesAvailable
Long-form
3
Proving, Applying Laws of Sines/CosinesAvailable
Long-form

Similarity Transformations · Deciding Similarity via Similarity Transformations

2 core skills2% total weight
0/2 completed
2 skills to mastery
1
Dilations Change Length by Scale FactorAvailable
Long-form
2
Dilations Keep Lines ParallelAvailable
Long-form

Similarity Transformations · General Skills

2 core skills3% total weight
0/2 completed
2 skills to mastery
1
AA Criterion from Similarity TransformationsAvailable
Long-form
2
Triangle Similarity Theorems and Pythagorean TheoremAvailable
Long-form

Modeling with Geometry

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Applying Density in Modeling SituationsAvailable
Long-form
2
Modeling with Geometric Shapes and PropertiesAvailable
Long-form
3
Using Geometry to Solve Design ProblemsAvailable
Long-form

Theorems About Circles

4 core skills6% total weight
0/4 completed
4 skills to mastery
1
Circle SimilarityAvailable
Long-form
2
Circle Relationships: Angles, Radii, and ChordsAvailable
Long-form
3
Constructing Tangents to CirclesAvailable
Long-form
4
Constructing Inscribed and Circumscribed CirclesAvailable
Long-form

Coordinate Geometry Proofs

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Proving Theorems with Coordinate GeometryAvailable
Long-form
2
Coordinates to Find Perimeter and AreaAvailable
Long-form
3
Partitioning Line Segments via RatioAvailable
Long-form

Geometry & Conic Sections

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Derive Equations of Ellipses and ParabolasAvailable
Long-form
2
Derive the Equation of a CircleAvailable
Long-form
3
Derive the Equation of a ParabolaAvailable
Long-form

Congruence & Rigid Motions

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Congruence via Rigid MotionsAvailable
Long-form
2
Theorems about Lines and AnglesAvailable
Long-form
3
Triangle Congruence from Rigid MotionsAvailable
Long-form

Model Periodic Phenomena

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Constructing Inverse Trigonometric FunctionsAvailable
Long-form
2
Modeling Periodic Phenomena with Trigonometric FunctionsAvailable
Long-form
3
Solving Trigonometric Equations in ContextAvailable
Long-form

2D–3D Relationships

1 core skills6% total weight
0/1 completed
1 skill to mastery
1
Cross-Sections, Rotations of 3D ObjectsAvailable
Long-form

Transformations in the Plane

5 core skills6% total weight
0/5 completed
5 skills to mastery
1
Defining Rotations, Reflections, and TranslationsAvailable
Long-form
2
Precise Geometric Definitions from Undefined TermsAvailable
Long-form
3
Representing Transformations as FunctionsAvailable
Long-form
4
Symmetries of Polygons: Rotations and ReflectionsAvailable
Long-form
5
Performing and Sequencing Rigid TransformationsAvailable
Long-form

Trigonometric Ratios & Right Triangles

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Deriving the Triangle Area FormulaAvailable
Long-form
2
Sine and Cosine of Complementary AnglesAvailable
Long-form
3
Solving Right Triangles: Pythagorean Theorem, TrigonometryAvailable
Long-form

Geometric Theorems

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Formal Geometric ConstructionsAvailable
Long-form
2
Theorems about TrianglesAvailable
Long-form
3
Theorems about ParallelogramsAvailable
Long-form

Volume Formulas & Applications

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Informal Arguments for Circle/Solid FormulasAvailable
Long-form
2
Informal Argument for Volume of SphereAvailable
Long-form
3
Solving Problems with Volume FormulasAvailable
Long-form

Geometric Constructions

2 core skills6% total weight
0/2 completed
2 skills to mastery
1
Properties of Dilations and Scale FactorAvailable
Long-form
2
Regular Polygons Inscribed in a CircleAvailable
Long-form

Polynomial Identities

1 core skills6% total weight
0/1 completed
1 skill to mastery
1
Proving and Applying Polynomial IdentitiesAvailable
Long-form

Trigonometric Identities

2 core skills6% total weight
0/2 completed
2 skills to mastery
1
Proving Angle Addition/Subtraction FormulasAvailable
Long-form
2
Proving the Pythagorean IdentityAvailable
Long-form

Theorems Involving Similarity

2 core skills6% total weight
0/2 completed
2 skills to mastery
1
Trigonometric Ratios from Right Triangle SimilarityAvailable
Long-form
2
Congruence and Similarity to Solve ProblemsAvailable
Long-form

Matrix Operations & Applications

2 core skills6% total weight
0/2 completed
2 skills to mastery
1
Using 2x2 Matrices for Plane TransformationsAvailable
Long-form
2
Zero and Identity Matrices and DeterminantsAvailable
Long-form