Lets play with circles now. There are three kinds of circles
  • circles with a midpoint, going through some point on the circle,
  • circles with a midpoint, and a radius equal to the distance of two other points,
  • circles with a midpoint, and a radius fixed by the user.

In this starting tutorial, you will only see the first kind. It is generated by selecting or creating two points,

  • one for the center,
  • and one on the circle.

 

Try to mimic that figure. To see how it works, click on the move tool, and move one of the flashing points. Then do the following to recreate the figure.

  • Start with an arbitrary, not too large circle with midpoint (let's call it M) through another point (let's call it A). You can even display the names, using the properties dialog (right mouse button). Change the name and enable the icon to display the name (the dot with the A).
  • Then create a circle with midpoint A through M.
  • You get intersection points on both sides, which are not yet construction points. Lay a circle around one of them through M. The intersection point will be created, if the mouse moves over the intersection. Note that both intersecting circles will highlight.
  • Continue, until you get the figure.

If you got lost, have a look on this page.

This ends our first tutorial!