Example 1
How is it possible for two circles to have only two common tangents?
Example 2
How is it possible for two circles to have only one common tangent?
Example 3
A diameter is a secant. True or false?
Example 4
If a line m is perpendicular to the radius of a circle, then m is not a secant of the circle. True or false?
Example 5
In the figure below, segments PB and PA are tangent to ⊙O at B and A, respectively. Also, ∠AOB is a right angle. Prove that ∠APB is a right angle.
