There are two Russian Army motorcyclists. In the section from a map given in our illustration below we are shown three long straight roads, forming a right-angled triangle at C.
The General asked the two men how far it was from A to B. Pipipoff replied that all he knew was that in riding right round the triangle, from A to B, from there to C and home to A, his cyclometer registered exactly sixty miles, while Sliponsky could only say that he happened to know that C was exactly twelve miles from the road A to B — that is, to the point D, as shown by the orange line.
Whereupon the General made a very simple calculation in his head and declared that the distance from A to B must be ______. Can the reader discover so easily how far it was?
