question_answer

A ladder leaning against a vertical wall makes an angle of \[45{}^\circ \] with the horizontal ground. The foot of the ladder is 3 m from the wall. The length of the ladder is?

A) 4 m                              

B) \[3\sqrt{2}\,\,m\]

C) 5 m                              

D) None of these

Correct Answer: B

Solution :

Suppose, The length of the ladder is x m. Then, \[\cos \,\,45{}^\circ =\frac{3}{x}\] \[\frac{1}{\sqrt{2}}=\frac{3}{x}\] \[x=3\sqrt{2}\,\,m\]