Drag any vertex. Every angle, length, rise, and run updates live. Switch between roof pitch, stair layout, and the 3-4-5 right triangle that every tradesperson carries in their head.
The Pythagorean theorem is a daily tool. a² + b² = c² — that's every rafter, every stair stringer, every diagonal brace. If you know any two sides, you know the third. If your triangle satisfies 3-4-5 (or 6-8-10, or 9-12-15), your corner is square.
Roof pitch is rise over run. A "6 in 12" pitch means: for every 12 inches of horizontal run, the roof rises 6 inches. That ratio determines rafter length, cut angles, and how snow loads.