This applet allows students to discover the relationship between the chord of a circle and the line perpendicular to that chord.

1. Drag the endpoints of the chord around the circle and check off the boxes to discover the relationships between the chord and line perpendicular to it.
2. If a line is perpendicular to a chord of a circle what point of the circle does it pass through? What is the specific name of this line segment?
3. What is true about the radius or diameter of a circle if it is perpendicular to a chord of the circle?