This is a stylized drawing of the St. Louis Gatew

This is a stylized drawing of the St. Louis Gateway Arc. the base of the St. Louis Gateway Arch is 10 units long (for some unknown unit). The designers that created the arch used the cosh(x) as their inspiration. let us assume that the St. Louis Arch follows 10-cosh(x) perfectly (the origin is at the middle of the base). Now let's say we wanted (and were physically able) to walk from the end over the top of the arch to the other end. Keeping the arch as our pathway the whole time, how many units would we walk if we were to do this?