Equal Chords

Below shows a circle, with centre O.
The points A, B, C, D and X are points on the circumference of 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 A, B, C and D to change their positions and the lengths of the chords AB and CD

Instructions:

1. Adjust the positions and lengths of the chords AB and CD so that they are equal in length.
2. Check the box.
3. Observe the perpendicular distances from the centre of circle to the chords AB and CD (i.e. OP and OQ).
4. Repeat steps 1 ~ 3 for other positions and lengths of the chords AB and CD.

Note: To see the animation, set the chords AB and CD to be of equal length and check the box, then click on the "play" button (at bottom left).



Download the GeoGebra file: http://www.geogebratube.org/material/download/format/file/id/41108

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