Topographer,

What do you expect the UCS to be when you draw the rectangle?

What do you expect the SnapAngle to be when you draw the rectangle ?

What information do you expect to provide to draw the rectangle ?

Without these answers explicitly you are wasting our time.

hi PKENEWELL. I use this unit settings. I didn't understand exactly your question . When i pick 2 points i can calculate the angle

Calculate the angle relative to what ?

added:

The SQUARE is easy .. The sides length and orientation are related to the diagonal line because of the diagonal bisects the 90 deg corner.

Have a think about the information you need to provide for the rectangle.