Geometry: Free Online Course & Practice
Angles, triangles, congruence, similarity, measurement, circles, transformations, coordinate geometry, and proof.
High school and placement prep5 units41 lessons + 9 assessments2333 practice & quiz itemsFree
Item counts include repeats and variants. There are 2316 distinct prompt texts after removing variant labels; this is not a count of unique mathematical skills.
Not sure where to start? Take the free 15-minute placement check to identify possible gaps, then practice with instant feedback and worked solutions.
Take the free Geometry placement check Open the Geometry courseStarting point and intended outcomes
Suggested preparation: Algebra I equations, coordinate graphs, and proportional reasoning.
Learning goals: Use geometric relationships, measurement, coordinate methods, and justified arguments. Written proofs and constructions require review beyond an automatic quiz.
These describe the course's intended scope. A score on one screen or final is only one piece of evidence about these goals.
Course 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
- Geometry Midterm Exam
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
- Coordinate Geometry and Transformations Checkpoint
- Proof and Coordinate Reasoning Checkpoint
Probability
- Conditional Probability and Independence
- Geometric Probability
- Geometry Probability Checkpoint
- Geometry Final Exam
Frequently asked questions
Is the Geometry course free?
Yes. The entire Geometry course — 50 lessons, 2333 practice and quiz items, including repeats and variants, 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 50 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 choose lessons to try first.
How do I find my gaps in Geometry?
Take the free Geometry placement check. It samples selected skills and suggests a practice plan. Skipped or untested topics remain unassessed; this is not a validated readiness certification.