Show total number of related records?

Show total number of related records?

I am new to SugarCRm Development. I built a custom module for Projects,
Project Tasks, and Project Files.
Projects has a One to Many Relationship with Project Tasks, and Project Files
So when you view a Projects ViewDetails page, it has 2 subpanels for the 2
other modules.
What I would like to do is on the Projects page, show some stats about the
other items. For example I would like to show...
the total number of Project Files related to the current project.
the total number of Project Tasks related to the current project.
the total number of Project Tasks marked as completed.
I know how to edit a variable in the Project view and make it use my
custom code, I just don't know how to get the data I am after to insert
into that place.
Any help in the right direction would be great, thank you