Question 385218
3 tangents - the circles are touching at 1 point. there are 2 external tangents and 1 internal tangent going thru the point where they touch

2 tangents - the circles are overlapping like a venn diagram - there are 2 external tangents

1 tangent - one circle is inside of the other and they are touching at exactly one point. the tangent is on the outside of both circles going through that point. 

0 tangents - there is one circle completely inside of another circle