Can anybody finish the puzzle #14 ? ?

With each iteration, you're swapping the two coordinates, and then change sign of the first one:

First transformation

Start with (3,1)Swap coordinates: (1,3)Change sign of the first coordinate: (-1,3)

Second transformation

Start with (-1,3)Swap coordinates: (3,-1)Change sign of the first coordinate: (-3,-1)

Third transformation

Start with (-3,-1)Swap coordinates: (-1,-3)Change sign of the first coordinate: (1,-3)

A’b’c’ are the coordinates to the new location of the transformed triangle abc. find the distance between the coordinates points to use for your calculations.