[b]Perpendicular Line from Centre Bisects Chord[/b]

[b]Perpendicular Line from Centre Bisects Chord[/b][br][color=#1551b5][/color][br]By moving points A or B you can adjust the lenght of chord AB.[br]D has been automatically set to the mid-point of AB.[br]Note that the angles ODB and ODA are right angles.[br][br]The converse is true:[br][b]The perpendicular bisector of a chord will passthrough the centre of the circle.[/b][color=#c51414][/color]