Question

A ladder is leaning against a wall such that its upper end touches the wall of the height of 3 m and the ladder is inclined at an angle having measure of 30${}^o$ with the ground. The length of the ladder is:

• A. $3$ m
• B. $6$ m
• C. $9$ m
• D. $12$ m

Answer 1

The correct option is B $6$ m

In the figure, AC = ladder, AB = wall = 3m, $\angle$ACB = 30${}^o$

In $△$ABC, sin 30${}^o$ = $\frac{AB}{AC}\Rightarrow \frac{1}{2}=\frac{3}{AC}\Rightarrow$ AC = 6 m.

$\therefore$ The length of ladder is 6 m.