Join our CAD community forums where over 25,000 users interact to solve day to day problems and share ideas. We encourage you to visit, invite you to participate and look forward to your input and opinions. Acrobat 3D, AutoCAD, Catia, Inventor, IronCAD, Creo, Pro/ENGINEER, Solid Edge, SolidWorks, and others.
A CATIA CATPart file is a 3D model of the part that probably does not include dimensions and notes as you would find on a drawing. If I understand your question, the answer is you cannot view a 3D CATPart as a 2D drawing.
But, you have several options, assuming you have CATIA software:
you could look at it in 3D and rotate/zoom, measure various lengths, etc.
or you could quickly create a new drawing based on the 3D geometry, but you would have to add your own dimensions and notes.