Intersection of secants in a circle
Theorem: If two lines intersect at point and intersect a circle at points and respectively, then =
Drag the blue points to the following configurations and see the products and . In each case, see why the corresponding angles in the blue and brown triangles are congruent.
- M - outside the circle;
- M - inside the circle;
- M - on the circle;
- P=Q and R different than S;
- P=Q and R=S