Non concentric circles are circles that do not share the same center point.
infinite with each one slightly larger than the previous
Farmers had more control over their crops than with sharecropping.
If you share with your circles, only your circles can see what you've posted. Extended circles includes people who are in your circles' circles. (Hope that makes sense!)
If they are in the same plane, then they share a common plane. Did you mean to say common point. If that's the case where they are in the same plane, but do not share a common point, then they are parallel lines.
Concentric circles - are circles that share a common centre. A typical example - is dripping water into a bowl - where you'll see the ripples form and spread out to the edge of the container.
Yes, circles that share one and only one point are tangent to each other.