Some of the measurement options display graphical feedback on the drawing while you select elements. The measured values are displayed as output in the Measure dialog box.
The results of a measurement can be used as inputs for other Creo Elements/Direct Annotation actions, for example, specifying lengths for added geometry. Since Measure is an interrupt function, invoking it while doing another operation does not terminate the current operation.
Click Apply or to use the output from Measure as input for the interrupted operation.