A ladder leaning against a wall makes an angle of 60° with the horizontal. If the foot of the ladder is 2.5m away from the wall, find the length of the ladder.
Solution:
Let AC be a ladder, AB is the wall and BC is the ground as shown in the figure. We know that cos60° = BC/AC 1/2 = 2.5/AC AC = 5 m Therefore, the length of ladder is 5 m.