Height and Distance
1.0 Introduction
1.0 Introduction
An application of trigonometry- heights and distances
Trigonometry is very interesting and helpful in measuring the height of tower or peak or the distance of a ship sailing in the sea. We do not need any measuring scale. All we need are the angle of elevation and angle of depression. We will explain the angle of elevation and angle of depression. Lets us become familiar with the following terms which will be used in the problems.
$(i)$ Line of sight: It is a straight line from our eye to the object.
$(ii)$ Angle of elevation: If an object is placed above the horizontal line from our eyes then we have to raise our head to view the object. In this process, our eyes move through an angle which is formed by the line of sight and a horizontal line which is called the angle of elevation.
$(iii)$ Angle of depression: If an object is placed below the horizontal line from our eye, we have to lower our head to view the object. In this process, our eyes move through an angle. This angle is called the angle of depression. The angle of depression of an object viewed is the angle formed by the line of sight with the horizontal line when the object is below the horizontal line.
There are few points which are to be kept while solving problems:
$(i)$ Read the question carefully.
$(ii)$ According to the given conditions mentioned in the question, construct the diagram for better understanding and visualization of the question.
$(iii)$ Identify the trigonometric ratio which will be useful to solve the problem.
