Question

A chord of a circle of radius 10cm subtends a right angle at its centre. The lenght of chord in cm is??

Answer 1

let O be the centre of the circle and let A and B be the two ends of the chord AB...so IN Triangle AOB..angle AOB=90..so Triangle AOB is a right angled triangle..so now using Pythagoras theorem..ABsq.=OBsq. +OAsq....also we know tht the length of the radius of the same circle are equal so...OA =OB...so..ABsq. =OBsq. + OBsq.=100 +100=200.so...AB =10√2cm(ans).