If I drive the lenght of 3 acres in a straight line, then how many miles does that equal?

Answer 1

Totally ambiguous question.

An acre is a unit of area.
It could be a square, or a long skinny rectangle, or even circular.
Are you talking about the US survey acre or the imperial acre?

One definition of an acre is an area of 4840 square yards.

Also did you know that one acre is the amount of land one man could plow in one day behind one ox ???

Go metric young man!