How do you make a solid in SketchUp?

Why is SketchUp not solid?

In order for a component to be considered solid it must contain only faces and edges. No other components or groups inside the container.

How do you make a 3D model of solids?

To Create a 3D Solid by Extruding

1. If necessary, on the status bar click Workspace Switching and select 3D Modeling. Find.
2. Click Solid tab > Solid panel > Extrude. Find.
3. Select the objects or edge subobjects to extrude.
4. Specify the height.