How to decide frame perimeter on Rhino Treads?

[ProfessorAlekM]

We just got Rhino Treads for our robot, but we need to figure out the frame perimeter of them so we can make the center braces the correct length.

In the rule manual it says:

To determine the FRAME PERIMETER, wrap a piece of string around
the ROBOT at the BUMPER ZONE described in R22. The string
describes this polygon.

So would my frame perimeter be a string wrapped from the center of the front bumper and back bumper so that it will be diagonal?