The shortest distance from Roberts home to his office can be found by using the Pythagorean theorem. The triangle that is created is a right triangle. We need to solve for the hypotenuse, the side directly across from the right angle created from this scenario. This Theorem says a^2+b^2=c^2, so 4x4+6x6=c^2. 52=c^2. The square root of 52 is approximately 7.2 km.