In addition to xcad's good info:
To measure a particular surface
- Analysis > Measure > Area
- Select the surface
- This will give the value
- Click the Add Feature button
- Enter the name (say: Analysis1)
- In your relations, add:
surf_area=area:FID_Analysis1
Where surf_area is your parameter name, FID means Feature ID (or something), Analysis1 is the feature name.
Then add a note:
Surface area = &surf_area
(Notes - this may require certain special Pro/E modules to add the Analysis feature. Also, it'll usually require a regen after changes to get the correct value.)
Merry Christmas
Ed