When a dimension measures a distance in perspective view, circles appear where the dimension connects to the model. Tip: In a SketchUp model viewport, the dimensions display subtle hints about what the dimension measures, as shown in the following figure. In Callouts B and C, you see a projected distance in an orthographic view. To show projected distances, make sure your model is in a standard orthographic view. In the following figure, the dimension in Callout A shows an actual distance because the model is in an angled Perspective view. Perspective view, in a nutshell, means the view is at an angle. A model in an orthorgraphic views displays a projected distance.
![marking flag insertion tool marking flag insertion tool](https://www.tracerelectronicsllc.com/page4/page-36/files/small_252.png)