You can use this function to make entities joined in the form conforming to actual scenario.

Join two entities:

1. Click Join, select the two intersecting entities you want to join, right click to confirm.
   
2. Click the green parts, and they will disappear.
   
3. Right click to confirm, and the two entities will be joined in the following form.
   

Use a line as the cutting line:

1. Click Join, select the entity you want to join, right click to confirm.
   
2. Select the cutting line (it could be the axis, entity sideline or drawing line).
   
3. The entity will be cut along the selected cutting line.