Analyze a design > Measure > Properties > To measure a face
  
To measure a face
1. Click Analysis and then, in the Measure group, click Face. The Measure Output and Face Props dialog boxes open.
2. Click the face you wish to measure.
3. Select a measuring option:
◦ Click Area in Calculate.
◦ Click Centroid in Calculate.
4. To set a specific tolerance, select the Percent check box and type a value.
5. To measure other faces, click Face and click a face.
6. Click the green arrow button to send the measurement to a command.
7. Click the green arrow and calculator button to send the measurement to the calculator.