Geometry
Reason about shape and space: angles, triangles, the Pythagorean theorem, and proof.
Mr. Thomas Bauer
Geometry Instructor
The Pythagorean Theorem
Find the missing side of a right triangle.
Angles & Lines
Classify angles by how far they turn.
The Pythagorean Theorem
The rule that links a right triangle's sides.
Area & Circumference of Circles
Measure round shapes with π.
Common questions
Who is "Geometry" for?
It is written for learners at High School level (Grades 9–12), and for anyone older who wants a clear refresher on mathematics. Reason about shape and space: angles, triangles, the Pythagorean theorem, and proof. There is no application or entry test — you can start the first lesson straight away.
How long does the course take?
There are 4 lessons totalling 30 minutes of reading and quizzes, laid out over 2 units. You can move at your own pace — progress is saved as you go.
What do I need to know before starting?
No prior coursework is assumed. The course opens with "Angles & Lines", covering parallel lines and transversals, so the foundations are built in rather than expected.
Is the course free?
Yes. Every course on Monster Class is completely free, with no credit card, trial period or paywall. Creating a free account simply saves your progress, XP and place on the leaderboard across devices.