Ron L wrote:

Not true. The length from handle pivot to the socket is still longer (triangle hypotenuse), though insignificant with a short extension

Actually because torque is a rotational force, at 90 degrees the effective length of the extension is 0. My engineering mechanics courses were a good many years ago, but if you search for it, I'm sure you can find the formula for the calculation.

Or maybe some of our practicing engineers can provide it.