To determine the angle of elevation of a road with a percentage grade of 7%, what function would be most helpful?

Question

Many mountainous areas have had road signs like this sign that refer to the percentage grade for the road. An 8% grade, for example means that the altitude changes by 8 feet for each 100 feet of horizontal distance.

Answer 1

θ = angle of elevation

 

tanθ = (% grade)/100

 

% grade = 7%

 

tanθ = 7/100 = 0.07

 

θ = tan^-1(0.07) ≅ 4.00°