A ladder leans against a wall with its foot 2 metres away from the wall and it makes a 40° angle with the ground. How high is the top of the ladder from the ground?
Let AC be the ladder which leans against the wall AB.
BC is the distance between the foot of the ladder and the wall.
So, in ΔABC, BC = 2 cm, ∠ABC = 90° and ∠ACB = 40°.
⇒ AB = BC × tan 40° … (1)
We know that tan 40° ≈ 0.8391 (From table)
Putting the value in (1):
AB ≈ 2 × 0.8391cm
= 1.6782 cm
Thus, the top of the ladder is at a distance of approximately 1.6782 cm from the ground.