Instructions:
Drag points T (tangent point), P, or Q around the circle.
The red pair and the blue pair show the two equal-angle relations of the Alternate Segment Theorem.
Theorem:
The angle between a tangent and a chord through the point of contact equals the angle in the opposite segment of the circle.
In this visualization:
- Angle (tangent, TP) = Angle TQP (red angles)
- Angle (tangent, TQ) = Angle TPQ (blue angles)