[list=1][*]Construct a circle.[br][/*][*]Construct a line through the centre of the circle.[br][/*][*]Construct the intersection points of the line and the circle.[br][/*][*]Construct the segment between the two intersection points.[br][/*][*]Hide the line through the centre.[br][/*][*]Construct a point on the circle.[br][/*][*]Construct a line parallel to the diameter passing through the point on the circle.[br][/*][*]Construct the intersections of the parallel line and the circle.[br][/*][*]Construct a segment between these intersections. This is a chord.[br][/*][*]Measure the chord and the diameter. Move both around. What is always true about the length of the chord and the diameter?[br][/*][/list]