Tools/materials: ipad Air 2, ipad IOS 13.2, fertility 4.3.8.
Method:
1. Open the software and select Calligraphy-Single Line in the brush library.
2. Then draw a circle on the canvas by hand or capacitor. It doesn't matter if it's not a perfect circle, but it must be closed.
3. Then click on the top to edit the shape.
4. Then select the circle.
At this time, you can see that the circle just drawn has become a perfect circle.
6. Then you can choose any color on the color wheel and fill it in.