Question

a chord of length 16 cm is drawn in a circle of diameter 20 cm calculate its distance from the centre of the circle

Answer 1

radius=10 cm
chord=16 cm
radius bisects chord (property)
therefore a triangle can be made 
the hypotenuse will be radius = 10cm
base will be 8 cm (bisected chord)
and using Pythagoras theorem the distance from centre of circle (i.e. Perpendicular) can be found out