Euclid Lab

Euclid Lab brings Book I of Euclid’s Elements to life through reading, hands-on construction, and proof practice. Read each proposition, explore its geometry with straightedge-and-compass constructions, and organize your ideas in a proof workbook.

Begin with 23 definitions, 5 postulates, and 5 common notions in Foundations. Then work through Propositions I.1–I.12 of Book I in order.

• Build and revise figures with straightedge, compass, intersection, and eraser tools.
• Undo or redo an action at any time, and review the complete construction step by step.
• Organize geometric relationships and reasoning in a proof workbook so your thinking stays clear.
• Create local learner profiles to keep progress, notes, and preferences separate on the device.
• Earn points and encouraging feedback the first time you complete an activity, and adjust the completion sound.

Euclid Lab is designed for learning primarily offline. No account is required, and learner profiles and progress stay on your device.

This version includes Foundations and Book I, Propositions I.1–I.12. Propositions I.13–I.24 and in-app purchases or content unlocking are not available in this version.