Circle Theorems (year 10)
Zoom into the circle that you want to look at, and drag the orange dot(s) around to demonstrate the theorems.
Drag the screen down to get the theorems about tangents.
I've left off explanations as people may want to phrase it differently.
1. Central Angle Theorem
2. Angles in the same segment
3. Cyclic Quadrilaterals
4. Semi circles
5. Tangent to a circle
6. Alternate Sector Theorem