Geometry-lesson.github Link -

Head over to (or check the repository on GitHub). Clone it, break it, fix it. And the next time someone tells you that the sum of the angles in a triangle is 180°, don't just nod.

Drag the vertex. Prove them wrong. (Spoiler: On a sphere, it’s more than 180°. We’ll cover that next week.) 👉 [Visit the Live Demo] 👉 [Star us on GitHub] geometry-lesson.github

Welcome to —where we stop guessing and start building. The Static Problem Traditional geometry lessons have a fatal flaw: they don’t move. Head over to (or check the repository on GitHub)

If you’ve ever tried to learn geometry from a static PDF or a dusty textbook, you know the struggle. You stare at a triangle on page 142, squint at the dotted lines, and wonder: "Does angle C really look like that? Or did the printer run out of ink?" Drag the vertex

You can’t grab a triangle and stretch its vertices to see if the angles still add up to 180°. You can’t rotate a 3D solid to see why the volume formula works. You’re expected to memorize, not manipulate.