Tangent Segment Theorem

Tangent Segment Theorem states that "Tangent Segments to a circle from a point outside the circle are congruent and the angles between the segments and the line segments joining the external point to the center of the circle are also congruent.
Note:
A. When two circles are tangent internally, the distance between the centers of two circles is equal to the radius of the bigger circle minus the radius of the smaller circle.
B. When two circles are tangent externally, the distance between the centers of two circles is equal to the radius of the bigger circle plus the radius of the smaller circle.