1 New raster layer

 

Shape → Bezier curve

Fill black

2 Trace the hair

3 Hair is completed

4 New vector layer

 

In the layer window

Click the vector layer icon

5 Trace the outline sketch of the face with a Bezier curve

6 Layer → Ruler Frame frame → Ruler from layer

If you erase a part with a vector eraser, all the connected lines will disappear.

 

Trace with pen tool