Girth (tack) strip down its center, it may cause discomfort. It is also best if it has some "give" to it, which makes it more comfortable for the horse. Many riders also choose a girth that allows for extra elbow room, so the horse is not restricted as his leg moves backward. To measure for a girth, the saddle with a pad should be placed on the horse. A measuring tape is then used to measure from the middle hole of the billet on one side, under the horse's belly, to the middle billet on the other side. If a girth is
Girth (geometry) width, with the same width "w". All curves of constant width have the same perimeter, the same value "w" as the circumference of a circle with that width (this is Barbier's theorem). Therefore, every surface of constant width is also a surface of constant girth: its girth in all directions is the same number "w". Hermann Minkowski proved, conversely, that every convex surface of constant girth is also a surface of constant width. For a prism or cylinder, its projection in the direction parallel to its axis is the same as its cross section, so in these cases the girth