# High school geometry

Missions recommend what to learn next, help you remember what you’ve learned by mixing skills, and save your progress.

Sign up### Staff picks

### Review articles

### Get Started

Intro to Euclidean geometry

Roughly 2400 years ago, Euclid of Alexandria wrote Elements which served as the world's geometry textbook until recently. Studied by Abraham Lincoln in order to sharpen his mind and truly appreciate mathematical deduction, it is still the basis of what we consider a first year course in geometry.
This tutorial gives a bit of this background and then lays the conceptual foundation of points, lines, circles and planes that we will use as we journey through the world of Euclid.

Start learning