A vertical summit curve has tangent grades of +2.6% and -1.5%. Using h1 = 1.37 m and h2 = 0.1 m, calculate the minimum length of curve if the required sight distance is 140 m.

A vertical summit curve has tangent grades of +2.6% and -1.5%. Using h1 = 1.37 m and h2 = 0.1 m, calculate the minimum length of curve if the required sight distance is 137 m.