casacamo:
In addition to the other suggestions, you can use a
Double Slanted Wall, leaving one side at 90˚ and setting the other side's angle to 96.2258° in this instance.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David