Puzzle A Dog Running Back & Forth

Created with MicroStation http://www.Bentley.com this clip presents a classic puzzle from the 19th-century puzzle master - Henri Dudeney (1857-1930} where a dog steps out with his master and runs back and forth between his master and their destination.
This can be solved using algebra of course, but that might mar the fun. Nothing like geometry, when it comes to visualizing motion! So here is a geometric solution with some animation capturing all the fun.

Видео Puzzle A Dog Running Back & Forth канала Ujjwal Suryakant Rane