The length of common chord of two intersecting circles is 30 cm. If the diameters of these two circles be 50 cm and 34 cm, calculate the distance between their centres.

Given that: Let the radius of the circle centered at O and O’ be 50/2 = 25 cm and 34/2 =17 cm respectively.

OO’ will be the perpendicular bisector of chord AB.

So, AC = CB

It is given that, AB = 30 cm

In, using Pythagoras Theorem

 …… (1)

Similarly,

In, using Pythagoras Theorem

   …… (2)

Thus,

Hence, distance between the centres is 28 cm.