[Chimera-users] measure the vertical distance between aromatic planes

Hi Chimera, Is there a way to measure the vertical distance of two planes in the structure? I do know how to measure the angle between two planes or one line and one plane by the Axes/Planes/Centroids in Chimera. I don't need the distance of two centroid of two planes. I do need the vertical distance of two planes. Could you please show me in detail? Thanks a lot! Bing Wang