Operations:
Step 1: click the “Draw” button and select the “Circle” command.
Step 2: specify the circle center by dragging or clicking on the drawing area.
Step 3: adjust center or click another point to specify the circle radius in drawing area.
Step 4: adjust radius or tap “✓” to confirm it.
Tips: The default is input radius. Click the diameter and radius icons in front of the enter bar to switch between two input modes.