A square plot is marked on a coordinate grid with corners at (2, 2), (2, 6) and (6, 6), and its sides run along the grid lines. Which pair gives the remaining corner?

Explication

The plot stretches from 2 to 6 in both directions, so its four corners pair the values 2 and 6 in every possible way, and the pairing not yet used is 6 across with 2 up. Naming a pair that already appears in the question repeats a corner and would leave the plot with only three of them.