Equidistant Chords

Below shows a circle, with centre O.
The points P and Q are points inside the circle.

You can:

• shift the point O to change the position of the circle
• shift the point X to change the size of the circle
• shift the points P and Q to change their positions (within the circle) and the lengths of OP and OQ

Instructions:

1. Adjust the positions of the points P and Q and the lengths of OP and OQ so that they are equal in length.
2. Check the box.
3. Observe the lengths of the chords AB and CD.
4. Repeat steps 1 ~ 3 for other positions and lengths of OP and OQ.

Download the GeoGebra file: http://www.geogebratube.org/material/download/format/file/id/41109

Download the Worksheet: http://db.tt/jJ5lR6ai