UPSC CDS Math Circle Questions

Let O be the centre of the circle.
Draw OC ⊥ AB.
OC is the distance of the chord ABfrom the centre of the circle.
OB = Radius of the circle = 17 cm
BC=AC=

30

2

=15cm
(Perpendicular from the centre to the chord bisects the chord)
In ΔABC,
OC=√OB2−BC2=√172−152
=√289−225=√64=8cm