Please explain the steps to solve and answer

The westbound U.S. Highway 74 truck route through North Carolina near the Tuckaseegee River has a downhill grade of 5%, (a) Explain what a 5% downhill grade means. A 5% downhill grade for a segment of road means that the decrease in elevation of the road over the segment is 5% of the change in horizontal distance over the same segment. In other words, for every horizontal feet, the road descends 5 feet, so the road has a slope of vertical feet per horizontal foot. Find the angle of descent for the road using the tangent function. (Round your answer to two decimal places.) (b) Explain how you could have used the cotangent function to have found the answer to part (a). The cotangent function would relate the horizontal change to the vertical change of the road, so we could have used the equation cot(0) = instead of tan(0) = (c) What is the elevation change over 2.5 miles on a road with a 5% downhill grade? feet