From a ship at sea level

MATHEMATICS · Subjective · CBSE · Mathematics · Applications of Trigonometry · Applications of Trigonometry

Problem

From a ship at sea level, the angle of elevation of the top of a lighthouse is observed to be

20^{\circ}

. After the ship sails 200 m directly towards the lighthouse, the angle of elevation becomes

40^{\circ}

. (Take

\tan 20^{\circ}=0.364

and

\tan 40^{\circ}=0.839

.) (i) Calculate the height of the lighthouse. (ii) Determine how far the ship was from the foot of the lighthouse at the first observation.