Common Tangents
A common tangent is a line that is tangent to two circles. All of the lines shown in the figure above are common tangents.
Do two circles always have to have four common tangents?
Time to experiment.
Move points A,B,C, and D on the circle and observe the common tangent lines.
Is it possible to have zero common tangents between two circles? Explain your thinking.
Is it possible to have exactly one common tangent line between two circle? Explain your thinking.
What is the maximum number of common tangent lines two circles could have?