Euclid Quest

Prove it — one tap at a time.

Euclid Quest turns classical geometry proofs into a calm, paper-and-ink puzzle game.

No typing, no formulas to memorize upfront: tap the angles, segments and triangles in the figure, pick a theorem, and watch your proof grow line by line until Q.E.D.

HOW IT PLAYS • Tap elements in the figure, then choose the reason — every step is a real geometric inference • Equal values carry over automatically and appear right on the figure • Stuck? A hint can highlight what to select, and the free theorem guide shows a worked example for every rule

WHAT'S INSIDE • A hand-crafted main journey across 6 chapters: vertical angles, parallel lines, triangles, congruence, circles and more • Thousands of extra practice puzzles in the puzzle bank, with fresh daily picks • A gentle tutorial guided by Euclid himself • Full offline play — proofs work anywhere • Available in English, 繁體中文, 简体中文, 日本語, 한국어, Español, Français and Deutsch

For working adults who miss the satisfaction of a clean logical argument, students who want geometry to finally click, and anyone who enjoys puzzles with real substance.

Every proof ends the same way: Q.E.D. — and it feels earned.