A small circle has the shape of a small circle. You're invited to position the center of the circle. This is shown in the upper left corner of the yellow Assistant palette. In fact the instructions there point out that you can also hit the TAB key instead of clicking on the screen, if you prefer to enter a numeric value for the X, Y and/or Z location of the circle's center. We will use this numeric input feature shortly, but for right now, let's just click approximately in the middle of the work bench to position the circle there.

Once you've click the mouse (left button), the circle's center is fixed there. A rubberband circle appears and resizes as you move the mouse. Notice that you no longer see the X/Y/Z value in the lower-left numeric display area. Instead, you're now seeing the radius, which changes when you move the cursor. You can now either click again to fix the circle's radius. Or, hit the TAB key and enter the desired radius numerically. Let's choose in this case to enter the numeric value. But what if you accidentally already clicked the mouse button a second time, and have thus already set the radius? No problem. You can back out step by step from the last operation in the circle tool simply by hitting the BACKSPACE key.

When you're at the point where it's asking you to set the radius, hit the TAB key, and enter 10.5 (without the apostrophe), then hit the Enter key to validate. Don't bother entering the units, which are cm (centimeters) by default. You can change them to inches or others in the Preferences menu if you want. (Edit > Preferences > Measurement Units).

At this point, the radius of the circle is set, and the tool asks for how many points you want to display on it:

You can again use the TAB key to set that value or, better, as the cursor indicates, use the plus and minus keys (+/-) on the numeric keypad to change that value. This is one of the nice and handy features in Amapi: Quite often throughout many tools, a choice can be made to select among several options, or a value can be changed, with the +/- keys. In this case, use the +/- keys to increase (thus with the '+' key) up to 12 points. When you're done setting the desired number of points, hit the Enter key. Or, you can also simply swipe the tool away to the right edge. Done!