# Quality of the documentation, cube command as an example

Heikki Höijer shared this question 4 years ago

I must say, as a beginner using Geogebra, that the documentation is confusing.

Example: You want to draw a cube, with vertices (0,0,0),(4,0,0),(4,4,0),(0,4,0),(0,0,4),(4,0,4),(4,4,4),(0,4,4). My first try was

cube[(0,0,0),(4,0,0),y=4],

because documentation says: "cube[<point>,<point>,<direction>], where direction can be a plane parallel to the segment between the points". But the cube created was “(0,0,0), (4,0,0), (4,-4,0), (0,‑4,0), (0,0,4), (4,0,4), (4,-4,4), (0,-4,4)”.

The cube I wanted I got after 15 minutes of trying and thinking:

cube[(0,4,0),(4,4,0),y=0].

So the when looking towards the x-axis, the segment must be on the right side and the plane on left side. How could I have known that? The documentation does not say how the segment and plane really determines cube. Where can the true, complete documentation be found?

Think cube[(0,4,0),(4,4,0),y+z=0]. What are the rest 6 vertices of the cube? How are determined! Why the documentation is so poor?

All you friends of Geogebra, please don’t be upset. I just want Geogebra to be better! 1

Hi,

I think the simpler in your case is to use Cube[(0,0,0),(4,0,0),(4,4,0)] as described in the documentation.

Issue you had with planes y=4, y=0 or y+z=0 is due to the fact that direction of the plane can be out in two opposite directions. To avoid that I recommend to use a vector for direction (so you will really now the direction it goes) or (simpler way IMHO) use the three first points of a face as described above.

Cheers,

Mathieu