Q8 of 164 Page 50

A ladder makes an angle 30° with the floor and its lower end is 12m away from the wall. Find the length of the ladder.


Let AC be the length of the ladder.


AB is the distance between the foot of the ladder and the wall = 12m


In ΔABC,


⇒ cos 30° =


⇒ cos 30° =


From cosine table, cos 30° = 0.8660


⇒ 0.8660 =


⇒ AC = = 13.856 m


∴ The length of the ladder is 13.856 m.


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