Question

Two circles of radii 5 cm and 3 cm intersect at two points and the distance between their centres is 4 cm. Find the length of the common chord.

Answer 1

R = 5 cm, r = 3 cm. d = 4 cm. 

length of the common chord = ?

When measured Chord CD = 6 cm. 

Circles with centre A and B, intersect at points C and D. 

CD is common chord. 

Perpendicular bisector of CD is AB. 

AC = 5cm. 

BC = 3cm. 

∴ Chord, CD= 2 × OC 

= 2 × 3 

∴ Chord, CD = 6 cm.