I hope this is clear enough.
Feel free to ask followup questions.
Options for Context Menu > Area
• Area of a Selection
Select one or more faces.
This option displays the area of the selected faces.
This option applies only to selected geometry in the current modeling context.
It does not apply to the face area of selected Groups or Components.
• Area by Layer
Select one face.
This option displays the area of ALL faces in the model assigned to the same layer as the selected face.
• Area by Material
Select one face.
This option displays the area of ALL faces in the model bearing the same material as the selected face.
A Face has two material attributes. Use Area by Material with caution!
A Face has a front side and a backside and each side has its own unique material attribute.
Paint “Red” on both front and back of a 1m x 1m face.
Area > Material for “Red” material = 2m sq. not 1m sq.
Groups and Components have one material attribute.
When a Group or Component is painted from outside its context, ALL default material faces (FRONT and BACK) within the context of the group display the group’s material attribute.
Model a cube 1m x 1m x 1m
Select the cube > Make Group
Paint the Group with “Red” material (from outside)
Materials Browser > In Model > Context click on “Red” material > Area = 12m sq. not 6m sq.
You can investigate this by viewing the material attributes of the Group and faces within the Group in the Entity Info box.
All your components are painted from outside.
Thus, Area > Material = The sum of all default faces (front and back) inside the components.
Re-paint the Components with the Default material.
Then edit each component and paint the individual faces within them.