What concept relates rise and roll in plumbing calculations?

The concept that relates rise and roll in plumbing calculations is true offset calculation. True offset calculations are crucial in plumbing design as they determine the actual distance a pipe needs to be run when changes in elevation or direction are required. Specifically, these calculations take into account both the vertical change (rise) and the horizontal travel (roll) of the pipe, which help ensure that drainage systems function correctly by maintaining the necessary slope and preventing backflow or stagnant water.

Understanding true offsets is particularly important when dealing with angled pipe runs or when navigating around obstacles. This ensures that all fittings and pipe lengths are accurately measured and cut, allowing for a smooth and efficient installation process. In contrast, other concepts such as angle determination, pipe leveling, and fitting measurements may relate to specific aspects of plumbing but do not directly address the combined effect of vertical and horizontal adjustments in pipe runs like true offset calculations do.