Differet elevation of ellipse's center and axes

[Karol-Or]

How come an ellipse, and maybe a circle, has a different elevation (y value in my drawing) than the major and minor axis?

[Kent1Cooper · Accepted solution]

If I understand correctly what you're asking, it's because what's shown in the Properties palette are major and minor half-axis vectors, which are World Ccoordinate values in relation to the Ellipse's center, not in relation to the origin of either the WCS or the UCS at the time it was drawn.  That Ellipse's major axis endpoint [the defining one] is 101(ish) units up in the Z direction from the center, and its minor axis endpoint is 22(ish) units to the left in the X direction from the center.  If you Move it in any or all of the XYZ directions [for example, change its elevation, whatever is meant by that when it's not parallel to the WCS plane], those won't change.

In entity-data terms, the major half-axis vector is in the 11-code entry [yours has not-quite-exactly-zero values for X and Y], but the minor half-axis is not stored as a vector value in XYZ coordinates, but as a ratio of its length to the length of the major half-axis, in the 40-code entry.

[Karol-Or]

Thank you very much Kent