Question

A train is chugging up a hill that has a 27 percent grade, which means that for every 100 meters it covers horizontally, it rises 27 meters. What is the angle of inclination?

Answer 1

The inverse tangent function takes slope y/x as input and outputs the angle. The output angle is limited to half a circle.

Answer 2

tan(x)=opposite/adjacent = 27/100
therefore, x = arctan(.27) = 15.1 degrees