By inserting a Workplane you can define a new workplane for a certain mesh. You can, for example, insert a diagonal plane as a complement to the horizontal and vertical planes. Essentially, you are changing the X, Y, and Z axes around which edits are made.

To insert a workplane, follow these steps:

1. Click the Make editable button and click the component that you wish to modify. The component is now editable.
2. Click the appropriate Workplane button; there is a 2D tool that operates on the X and Y planes, and a 3D tool that operates on the X, Y, and Z planes.
3. Move the cursor to the drawing area. The cursor snaps to different places on the component, and a blue workplane is visible in 3D.
4. For the 2D tool, select two points on the component that you want to match your workplane to. Click once for X and Y:
   
   
   OR
   
   For the 3D tool, select three points on the component tab that you want to match your workplane to. Click once for X, Y, and Z.