The radius of a circle is 2.5 cm. AB and CD are two parallel chords 2.7 cm apart. If the length of the chord AB is 4.8 cm, then find the length of chord CD.
3 cm
Since the perpendicular from the centre of the circle bisects the chord, AP = 2.4 cm
Using Pythagoras theorem for ΔAPO, we can calculate PO=√2.52−2.42=0.7 cm
Since PQ = 2.7 cm and PO = 0.7 cm, OQ = 2 cm
Using Pythagoras theorem for ΔCQO,CQ=√2.52−22=1.5 cm
So, CD = 2CQ = 3 cm