If the resistors are arranged in a shape of a square, then they are in a series type of circuit. This circuit arrangement is a non-branching, one-way flow of electrons. The total resistance in a series circuit is the summation of the individual resistances, If you place the ohmmeter (measures resistance) on two non-adjacent sides, then, you are measuring the resistance of two of the resistors.
Resistance = 2(1 kΩ) = 2 kΩ
