The difference between the centerline of a vehicle and the line perpendicular to the rear wheels is called what?

The thrust angle is an imaginary line drawn perpendicular to the rear axle's centerline. It compares the direction that the rear axle is aimed with the centerline of the vehicle. It also confirms if the rear axle is parallel to its front axle and that the wheelbase on both sides of the vehicle is the same.

Uhh? is this it? message me id love to : )