Use the Measure tools to measure various dimension types associated with a model and its entities. When you select a measure tool and a reference entity, the pointer indicates the tool for the measurement. The Measure dialog box is an extension of a measure tool. It has all the Measure tools and the options for the selected measure tool. The title bar of the Measure dialog box shows the dimension type that you are measuring for example, Measure:Length. Using the options on the Measure dialog box, you can replace or remove entities for measurement.