You can use Point-to-Point mode to compare the distance between two faces at different places on the model.
- Open install_dir\samples\whatsnew\fundamentals\clip.sldprt.

- Click Measure
(Tools toolbar) or .
- In the Measure dialog box, click Point-to-Point
.
- Select a point near the center of one of the flat faces of the grip, and then a point near the center of the other flat face, rotating the model if necessary.
The measurement appears in the graphics area and in the Measure dialog box.

- Click in the graphics area to clear the current measurement.
- Select the midpoint of the top edge of the flat face of the grip, and then the midpoint of the opposite edge.
When you hover over an edge, the midpoint appears, allowing you to select it, like in a sketch.
The measurement appears in the graphics area and in the Measure dialog box.

- Click in the graphics area to clear the current measurement.
- Click Point-to-Point
to exit Point-to-Point mode.