Virtual rendering in terms of triangles

I have a computer graphics related question and wondering if anyone has any idea. One of our reviewers for our VR based manuscript has asked us to provide details of "virtual rendering in terms of triangles". My coauthor ran the study and used alienware 15' gaming laptop with 1920x1080 res to render the virtual environment for HMD: oculus rift CV1. She is not sure where to find the info about the triangles. Any idea?