A chord is at a distance of 8 cm from the centre of a circle of radius 17 cm. The length of the chord is
Given radius(AO) = 17cm
Length of the chord (AB) = x
distance of the chord from the centre is 8cm.
Draw a perpendicular bisector from center to the chord and name it OC.
AC = BC
Now in ∆ AOC
Using Pythagoras theorem
AO2 = AC2 + OC2
172 = AC2 + 82
AC2 = 172 – 82
AC2 = 289 – 64
AC2 = 225
AC = 15cm
BC = 15cm
The length of the chord is AC + BC = 15 + 15 = 30 cm.