NCERT · Class 10 · Mathematics · Applications of TrigonometryExplain the step-by-step methodology used to solve practical problems related to heights and distances in trigonometry, highlighting the importance of correct diagrammatic representation.
Solving practical problems based on heights and distances requires a systematic and disciplined approach, as the entire solution depends heavily on the initial interpretation of the word problem. The first and most critical step in this methodology is to read the given statement thoroughly and draw a neat, well-labelled geometric diagram representing all the given elements such as towers, poles, observers, angles of elevation, and angles of depression. Without an accurate diagram, it is nearly impossible to visualize the right-angled triangles involved. In the diagram, represent heights with vertical lines, grounds or distances with horizontal lines, and lines of sight with inclined segments. Once the figure is correctly drawn, identify all the right-angled triangles present in the figure. The next step is to choose an appropriate trigonometric ratio—such as sine, cosine, or tangent—that relates the known side or angle with the unknown side or angle that needs to be calculated. Generally, the tangent ratio ($\tan \theta$) is most frequently used because it directly connects the perpendicular (height) and the base (distance). Write down the trigonometric equation clearly and substitute the known numerical values, trigonometric table values (like $\sin 30^\circ = 1/2$, $\tan 45^\circ = 1$, etc.), and solve the algebraic equation step by step to arrive at the final required answer with appropriate units of measurement.