In the given figure, AP, AQ and BC are tangents to the circle. If AB = 5 cm, AC = 6 cm and BC = 4 cm then the length of AP is
(a) 15 cm (b) 10 cm (c) 9 cm (d) 7.5 cm
In a circle of radius 5 cm and centre O, AB and AC are two chords such that AB = AC = 6 cm. AO is the perpendicular bisector to BC. Find the length of the chord BC.