Answer: The angle of elevation X = 62.7 degrees
Step-by-step explanation: Please refer to the attached picture for details.
The ramp rising from the ground is given as line XZ which is 18 feet. Also it rises 16 off the ground which is also given as line YZ. The angle of elevation of the ground, that is, angle X is the angle formed at point X where the ramp begins to rise. We shall apply the trigonometric ratio to solve for angle X, having been given two sides of the right angled triangle. The side YZ is the line facing the reference angle (opposite) while the side XZ is the line facing the right angle (hypotenuse).
SinX = opposite/hypotenuse
SinX = 16/18
SinX = 8/9
SinX = 0.8888
From your calculator or table of values,
X = 62.7339
Rounded to the nearest tenth of a degree,
X = 62.7 degrees