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To measure length, area, and circumference, you have two options:
 * Using the Measuring Tool**


 * Click the **Ruler** icon in the toolbar (**Tools** > **Ruler**), check the **Mouse Navigation**box if it's not already checked, and click in the 3D viewer to start measuring. You can select different tabs within the measuring tool to change the shape (Path, Polygon, Circle) that you’re measuring with. The measurements will appear in the dialog box as you draw. Click **Save** to save your measurement as a KML file.