How to get the centre of mass of a face.

I can get the centroid of a Solid Body by using Measure Manager-newMassProperties.
But Its not possible with faces of the Body. I need the center of mass of the face.

One way to get the center of mass of a face would be to use the .AskMassProps3d method. Pass in a "2" for the type (thin shell) and provide a density value. The density value will be intepreted as mass per unit area for the sheet body.