Fundamentals > Creo Parametric User Interface > The Analysis Tab > Measuring Geometry > Measuring Entities > Using Specific Measurement Types > Distance > Using Reference Entity Options > About the Plane Option
About the Plane Option
If you select a planar surface as a measurement reference, with the Use as Plane option you can use the surface as a plane by extending the surface to infinity in both directions only for the purpose of measurement. The surface remains the same. The distance is measured between the plane that would be formed by extending the surface to the other selected entity in the normal direction.