Hi Sergio Mayorga,

In my opinion, the best way is:

- Select the wall
- Edit => Rotate
- Write the desired angle

To select the wall easily, you can draw a wall (horizontal or vertical), not connected with other walls, select it and rotate it as described above.
Then, select it again, and move it with the arrow keys, or the Edit => Move function, or with the mouse.
Be sure to use the mouse to set this wall to the next (so they will "glue")

Let us know if you need more help

Patricia