Question

To find the length of a ladder making an angle $\theta$ with wall, which trigonometric ratio is used?

• A. $\tan \theta$
• B. $\cot \theta$
• C. $\text{cosec}\theta$
• D. none

Answer 1

Answer: (C)

$\text{cosec}\theta$

Let $\overline{AB}$ is a wall and $\overline{AC}$ is a ladder.
A ladder makes an angel of measure $\theta$ with the wall.
$\therefore m\angle BAC=\theta$
$\therefore \sin \theta =\frac{BC}{AC}$
$\therefore AC=\frac{BC}{\sin \theta }=BC.cosec\theta$
Therefore to find the length of ladder trigonometric ratio $\text{cosec}$ $\theta$ is used .