Answer: The angle of elevation would be 36.87 degrees (approximately)
Step-by-step explanation: Please refer to the attached diagram for details
The 30-foot ladder reaches a point in the building which is point A. The height at which the ladder touches the building is 18 feet (that is, the height of the building, line AC. The angle of elevation from the ground is at angle B, the angle which the ladder forms with the ground.
So we have a right angled triangle ABC, with two sides and a reference angle B. To find angle B, we shall apply the trigonometric ratio;
SinB = opposite/hypotenuse
SinB = 18/30
SinB = 0.6
By use of a calculator or table of values
B = 36.8698
Approximately, angle B = 36.87 degrees
