From Secants to Tangents
1. Move point R closer to P. What do you notice?
2. Click on the line QP in the side margin (a red secant line should now appear passing through Q and P). Move point Q closer to P. What do you notice?
3. Click on the line QR in the side margin (a green secant line should now appear passing through Q and P). Move point Q and R closer to P. What do you notice?