want to calculate major axis of an ellipse but struggling with equations!

Hi!

I have a circle that is tilted 23.5 degrees so that an observer sees an ellipse.

I have the minor axis (b) of the ellipse (ie the height).

How can i use the degrees of tilt of the circle, to calculate the eccentricity of the observed ellipse. Then I can use eccentricity and minor axis to calculate the major axis (width)

Thanks!

I have looked at the equations on this page

Ellipse - Wikipedia, the free encyclopedia

but i really don't even know what I'm looking for