Learn high school geometry—transformations, congruence, similarity, trigonometry, analytic geometry, and more (aligned with Common Core standards).

Explore geometry concepts including angles, shapes, transformations, and proofs with Khan Academy's engaging resources.

Created by experts, Khan Academy’s library of trusted, standards-aligned practice and lessons covers math K-12 through early college, grammar, science, history, AP®, SAT®, and more.

Get ready for high school geometry! Learn the skills that will set you up for success in congruence, similarity, and triangle trigonometry; analytic geometry; conic sections; and circles and solid geometry.

This Basic geometry and measurement course is a refresher of length, area, perimeter, volume, angle measure, and transformations of 2D and 3D figures. If you are learning the content for the first time, …

This Basic geometry and measurement course is a refresher of length, area, perimeter, volume, angle measure, and transformations of 2D and 3D figures. If you are learning the content for the first time, …

In this course, you’ll search for patterns, build and test conjectures, and prove your reasoning. You'll explore congruence and similarity through transformations, algebraic notation, and geometric …

Up next for you: Course challenge Test your knowledge of the skills in this course. Start Course challenge

Unit 9: Relating algebra and geometry Unit mastery: 0% Distance and midpoints Standard equation of a circle Expanded equation of a circle

Explore geometry concepts related to circles, including properties, formulas, and applications, through engaging lessons and exercises on Khan Academy.