# Tilt angle for a flat

1. Sep 3, 2010

### Ramar

Hi all,
a flat intersects with unknown tilt angle a Cartesian coordinate system into it's origin. Let's suppose the flat "rising" from negative Z values. We know:
- vertical angles between flat and X, Y axis, let's suppose 10° each;
- horizontal angle between tilt direction and axis. Because the vertical angles between flat and X, Y axis are identical this angle will be 45°;
I'd like to know how to calculate the angle between the flat formed by X and Y axis of the reference system, and the ideal stright line representing the tilt direction.
I hope I was clear....english is not my native language... .