In the figure,two circles with centres A and B of 5 cm and 3 cm touch other internally.If the perpendicular bisector of segment AB meets the bigger circle in P and Q.Find the length of PQ.
As the 2 circles touch internally,
∴AB = r1 - r2 = 2 cm
Also, PQ is the perpendicular bisector of AB.
∴AC = BC = 1 cm
In right ΔACP,
AP2 = AC2 + CP2
⇒52 = 12 + CP2
⇒CP2 = 24
⇒CP = 2√6 cm
Hence, PQ = 2CP
= 4√6 cm