Interactive geometry to use now

The widest angle The length AB represents a statue on a plinth. You are standing at C. Where should you position yourself to get the widest view of the statue (ie, the angle ACB is largest)? This is essentially Regiomontanus' problem, first proposed in 1471. If you can't see it, ask for a hint. Press "r" to reset the sketch. This problem is taken from "You Are A Mathematician" by David Wells (Penguin,1995)