Question

Question 19. Prove that: If two circles touch each other, then the point of contact will lie on the line
joining the two centres.​

Answer 1

Answer:

Theorem: If two circles touch each other (externally or internally), then their point of contact lies on the straight line joining their centers. ... Thus, both the perpendiculars AP and BP pass through the same point P, which necessarily implies that A, P and B are collinear.