1. ## tami1215

I have a question about distance. how big does a circle have to be for it to lokk like you're walking in a straight line? I can't find the answer anywhere and I don't know how to calculate the answer. Thank-you. T

2. Originally Posted by tami1215
I have a question about distance. how big does a circle have to be for it to lokk like you're walking in a straight line?
That is a purely subjective question.
The curvature is the measure of how quickly the tangent to the curve is changing direction. Because lines have curvature of zero, you are asking: how large does the radius need to be in order for the curvature is almost zero? How close to zero do you think do you need?

3. ## tami1215

I'm thinking a curve of less than 10 degrees?

4. ## tami1215

I'm sorry, I think my question is poorly phrased and causing some confusion. For me at least. I want to find the circumfence? of a sphere that is large enough that if I were to walk around it the curvature would not be noticable. But I also need to find the smallest sphere where that would be possible. Thank-you T