Wrong Side Trimmed


The left side is trimmed as it should be but the right side is trimmed the opposite.

 Dim Split As Geometry.Brep() = ElementBrep.Trim(TrimBrep.Brep, doc.ModelAbsoluteTolerance)

How can i determine that the other side is trimmed or change the trimmed part?
Split.Length is alwasy 1.

Nvm. Solved. Just changed trim to split and checked the size of the area that i want to keep.