actually, Pythagoras Theorem asserts that to determine the unknown side (hypotenuse) of a right triangle with short sides of length a (2 blocks) and b (2 blocks), the hypotenuse (c) would calculate as follows;
a (squared) + b (squared) = c (squared)
2 (squared) + 2 (squared) = c (squared)
4 + 4 = 8
c (square root of 8) = 2.828 blocks southwest