- Circle[ <Point>, <Radius Number> ]
- Yields a circle with given center and radius.
- Circle[ <Point>, <Segment> ]
- Yields a circle with given center and radius equal to the length of the given segment.
- Circle[ <Point>, <Point> ]
- Yields a circle with given center through a given point.
- Circle[ <Point>, <Point>, <Point> ]
- Yields a circle through the three given points (if they do not lie on one line).
| Following text is about a feature that is supported only in GeoGebra 5.0.
Note: From GeoGebra 5, this command will work in 3D with 3D Points as well
Use circles to fix the distance between two objects
Circles are a great way to make the distance between two objects constant: If there are two points A and B on two lines g (point A) and h (point B) where A can be moved and B should have the constant distance r to A you can define B as the intersection between the line h and the circle around A with the radius r. As a circle intersects a line at two points (in case it's not tangetial or passing by) you have to hide & ignore the second intersection.