Geometry: Free Online Course & Practice
Angles, triangles, congruence, similarity, measurement, circles, transformations, coordinate geometry, and proof.
High school and placement prep5 units45 lessons602 practice & quiz problemsFree
Not sure where to start? Take the free 15-minute placement check to pinpoint your gaps, then practice with instant feedback and worked solutions.
Take the free Geometry placement check Open the Geometry courseCourse outline
Geometry Foundations
- Geometry Vocabulary and Diagrams
- Logic, Conditionals, and Biconditionals
- Geometric Constructions
- Angle Relationships
- Parallel Lines and Transversals
- Triangle Angle Relationships
- Polygon Angle Sums
- Quadrilateral Properties
- Geometry Foundations Checkpoint
Triangles, Similarity, and Trigonometry
- Triangle Inequality and Side Relationships
- Congruent Triangles
- Triangle Congruence Shortcuts
- Similar Triangles and Scale Factor
- Similarity Applications
- Right Triangles and the Pythagorean Theorem
- Special Right Triangles
- Right Triangle Trigonometry Basics
- Law of Sines
- Law of Cosines
- Special Segments in Triangles
- Triangle Centers
- Triangles and Similarity Checkpoint
Measurement, Circles, and 3D Solids
- Area and Composite Figures
- Advanced Composite Measurement
- Surface Area and Volume
- Volume of Cylinders, Cones, and Spheres
- Cross-Sections of 3D Solids
- Circle Circumference and Area
- Arcs and Sectors
- Circle Angle Theorems
- Tangent, Secant, and Chord Angle Theorems
- Inscribed and Circumscribed Polygons
- Measurement and Circles Checkpoint
Coordinate Geometry and Proof
- Transformations on the Coordinate Plane
- Dilations and Similarity Transformations
- Distance and Midpoint
- Equation of a Circle
- Coordinate Proofs with Slope
- Coordinate Quadrilateral Proofs
- Proof Reasoning
- Two-Column Proofs
- Parallel Line Proofs
- Geometry Readiness Test
Probability
Frequently asked questions
Is the Geometry course free?
Yes. The entire Geometry course — 45 lessons, 602 practice and quiz problems, worked solutions, and the placement check — is free to use at ClearMath Academy.
What does the Geometry course cover?
Angles, triangles, congruence, similarity, measurement, circles, transformations, coordinate geometry, and proof. It spans 5 units and 45 lessons, each with a worked example and practice problems with step-by-step solutions.
Who is Geometry for?
Geometry is aimed at high school and placement prep. You can take a free 15-minute placement check first to find exactly which lessons to start with.
How do I find my gaps in Geometry?
Take the free Geometry placement check. It pinpoints the specific skills you're missing in about 15 minutes and builds a practice plan focused on those gaps.