Making a component.

This enables you to save your cube as a component which you can then replicate to build more complex objects or easily restore in the event of a major botch up.

Select the whole cube and then click the edit/make component menu.

Give your component a name and click create.

You can now make lots of cubes by using the window/components menu.

To view your components click on the in model option in the components menu.

Click your cube and then drag, drop and rotate to the position that you desire.

Making a Tetrahedron.

Select wireframe on the view/face style menu.

This enables you to see all the edges of your cube.

Click on the line drawing tool

Draw lines that join all the vertices A,B,C and D together.

The cube should now look like this.

The tetrahedron can be easily seen inside the cube. You now need to remove the surplus edges at the other vertices.
To select an edge you click on it. It should then go blue. Press ctrl x to delete it.

Your tetrahedron should look like this.

Save this as a component and then make several copies. Have a play with the other menus to see how you can colour or shade the faces etc.