Question

if in a circle of radius 5cm the distance of a chord from the centre id 3cm, then length of the chord is :-

a) 4cm b)6cm c) 8cm d)10cm​

Answer 1

The situation is described in the above diagram.

Kindly note that since the OC = radius = 5 cm.

Also, perpendicular from the centre of the circle to the chord = 3 cm.

Now, we have a right angled triangle OEC with two sides equal to 3 cm and 5 cm respectively.

Clearly, it is the 3,4,5 triplet !

Thus, the third side = EC = 4 cm.

But perpendicular from centre to the chord bisects it, so length of chord = DC = 2 x EC = 2 x 4 = 8 cm.

Hence,

Hence,c) 8cm is the correct....

MORAL : Life is really very easy

if we know PYTHAGOREAN TRIPLETS!