PreCalculusTrig
posted by Chloe Mack on .
A road rises 140 feet per horizontal mile. What angle does the road make with the horizontal?

Draw a triangle.
The the road would be the base, which is 1 mile or 5280 feet and the side opposite angle A would be 140.
You need angle A. You have side a = 140 feet, and side b = 5280 feet.
tan A = opp/adj = a/b = 140/5280
tan A = 140/5280 = ?
arctan ? = angle A