An observer 1.5 m tall is 20.5 metres.

An observer 1.5 m tall is 20.5 metres away from a tower 22 metres high. Determine the angle of elevation of the top of the tower from the eye of the observer.

Solution:

In the figure, AB is tower and CD is an observer.
θ is the angle of observation from

From a boat 300 metres away from a vertical cliff, the angles of elevation of the top and the foot of a vertical concrete pillar at the edge of the cliff are 55°40′ and 54°20′ respectively. Find the height of the pillar correct to the nearest metre.

Solution:

Let CB be the cliff and AC be the pillar
and D be the boat which is 300 m away from
the foot of the cliff i.e. BD = 300 m.
Angles of elevation of the top and foot of the pillar
are 55°40′ and 54°20′ respectively.
Let CB = x and AC = y
In right ∆CBD,

More Solutions:

• Solve the following trigonometric:
• Evaluate trigonometric:
• Solve trigonometric:
• Solve: (1 + tan A)/sin A + (1 + cot A)/cos A = 2(sec A + cosec A)
• Prove the identity:
• Solve: (sinθ + cosθ)(secθ + cosecθ) = 2 + secθ cosecθ.