I needed to know how to draw a simple circle in illustrator to then divide it in regular sections for my medieval stencils projects-
The tool to be used is the ellipse tool (same symbol as in Adobe Photoshop).
First of all, there are two ways to use this tool, here shown:
1. SHIFT + DRAG MOUSE
2. CLICK on work area without dragging the mouse: A new window will appear where you can set the parameters of the circle (a special ellipse having both axis identical).
2. Just click the mouse on the work surface with the ellipse tool selected...
But then of course there is the interesting way to draw a circle in a third way which also include the possibility of dividing the area of the circle in a precise set of parts (fractions),
The tool to be used is the POLAR GRID tool
The Polar Grid Tool
Again this tool can be used as the ellipse tool either by dragging it (HOLD SHIFT for a circle) or by clicking on the work area and set the parameters:
Width: width of ellipse/circle (X-axis)
Height. height of ellipse/circle (Y-axis)
Concentric Dividers: inner "circles"
Radial dividers: equal divisions (fractions)
Obviously, in a simple circle you set the same values for "width" and "height" while the other parameters both to zero.
Drawing a circle with the Polar gris. Parameters (concentric dividers and Radial Dividers) are set to zero
Otherwise, by setting the parameters as you wish, you get, well, yes...a polar grid!
Use the Rounded Rectangle Tool, click on the work area and set all parameters equal! Also experiment with it!