Interactive demonstration designed for the Silent Teacher method
Teacher Instructions:
Start with "Show Angles" active. Drag the blue point X around the circle in silence so students notice the invariant property.
Click Mode: On Circle to detach point X. This lets you show a non-example where the rule breaks (the angle changes).
In Part 5, use 📸 Snapshot Edge Angle to copy the blue angle. Drag the snapshots to the center O to physically stack two edge angles inside the center angle!