ISO/TS 10303-1631:2010-03 specifies the application module for
Area 2D.

The following are within the scope of
ISO/TS 10303-1631:2010-03:

• definition of primitive areas in two dimensional space;
• items within the scope of application module Extended basic geometry, ISO/TS 10303-1667;
• items within the scope of application module Value with unit extension, ISO/TS 10303-1753.