Interior and exterior is just a fraction of 360 degrees. Sine, Cosine and Tangent
5.9m or the wheel width is 'Adjacent'
Two numbers needed for 'Hypotenuse' and 'Opposite'
Using of the 6.1 from hitch as the 'Hypotenuse' seems reasonable. You added the 90 degree right angle to make it easy
We have two sides so you know the formula. Sing It loud
Colin Dodds - Pythagorean Theorem (Math Song) - YouTube

