RotateTransform is not applied correctly on elements defined in the Content of the window.

Reason for declining: The issue appears to be in the framework as it is not calculating correctly the transformation and instead of rendering the transformation it apply a Clipping to the parent element. You could solve the issue by two different approaches: you could either set the UseLayoutRounding of the Window to false, or set the Width/Height properties of you element to be Integer numbers, not double (10.782). You can reproduce the same behavior with the MS Window simply set its UseLayoutRounding to true. You can find attached project reproducing the issue only with MS controls.