Do straight lines exist?

Question

One of my teachers told me that straight lines don't exist, because the definition of a straight line is a circle of infinite radius.

BUT I don't think that's correct, because the radius of a circle is by definition the shortest distance from the center of the circle to the dge. Since it's the shortest distance, it must be a straight line. And without that straight line (radius), there cannot be a circle.

Your thoughts?

Answer 1

I'm not sure about what your teacher said, but I don not believe there is such a thing as a perfectly straight line because even though it may seem straight to the human eye it will always be the slightest bit curved