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