From the top of a church spire 96 m high, the angles of depression of t:vo
vehicles on a road, at the same level as the base of the spire and on he
same side of it are rº and yº, where tanto and tan jo
4
Calculate the distance between the vehicles.
Answers
Answer:
From the top of a church spire 96 m high, the angles of depression of t:vo
vehicles on a road, at the same level as the base of the spire and on he
same side of it are rº and yº, where tanto and tan jo
4
Calculate the distance between the vehicles.
We are given that from the top of tower 96m high, the angles of depression of two cars on a road at the same level as the base of the tower and on the same side of it are theta and phi, where tan theta =3/4 and tan phi = 1/3.
In the figure drawn below; let \angle ACB = \text{tan} \theta = \frac{3}{4} and \angle ADB = \text{tan } \phi = \frac{1}{3} and also the height of the tower = AB = 96 m.
Now, as we know that \text{tan } \theta = \frac{\text{Perpendicular}}{\text{Base}}
So, in \triangleABC,
\text{tan } \theta = \frac{AB}{BC}
\frac{3}{4 } =\frac{96}{BC}
BC = \frac{96 \times 4}{3}
BC = 32 \times 4 = 128 m
Now, in \triangleABD,
\text{tan } \phi = \frac{AB}{BD}
\frac{1}{3} =\frac{96}{BD}
BD = \frac{96 \times 3}{1}
BD = 288 m
So, the distance between two cars = CD = BD - BC
= 288 m - 128 m = 160 m.