Sector Areas (Radians)

Below shows a circle, with centre O.
The points A, B 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 and B to change their positions and the area of the sector OAB

Instructions:

1. Adjust the area of the sector OAB.
2. Check all the boxes.
3. Observe the values of \(\frac{\theta }{{2\pi }}\) and \(\frac{{{\rm{Area\;of\;Sector,\;}}OAB}}{{{\rm{Area\;of\;Circle}}}}\).
4. Repeat steps 1 ~ 3 for other areas of the sector OAB.

Note: To see the animation, click on the "play" button (at bottom left).



Download the GeoGebra file: http://www.geogebratube.org/material/download/format/file/id/47081

Download the Worksheet: http://db.tt/E3AvgdS1