Jitender Gupta and Divya Malik Solutions for Exercise 1: CHAPTER EXERCISE

What is the angle of elevation (in degree) of the Sun, when the length of the shadow of a tree is equal to its vertical height? 

The height of a tree is $\sqrt{3}$ times the length of its shadow. Find the angle of elevation (in degree) of the Sun.

An aeroplane when flying at a height of $4000 \mathrm{m}$ from the ground, passes vertically above another aeroplane at an instant, when the angles of the elevation of the two planes from the same point on the ground are $60°$ and $45°$, respectively.The vertical distance between the aeroplanes at that instant is $k \mathrm{m}$. Find $k$.

The radius of a circle is given as $15 \mathrm{cm}$ and chord $AB$ subtends an angle of $131°$ at the Centre $C$ of the circle, using trigonometry. Then the length of $AB=$_____$\mathrm{m}$. 

The radius of a circle is given as $15 \mathrm{cm}$ and chord $AB$ subtends an angle of $131°$ at the Centre $C$ of the circle, using trigonometry. iF the distance of $AB$ in  $k \mathrm{cm}$ from centre $C$, then find $k$.

The angle of elevation of a stationary cloud from a point $25 \mathrm{m}$ above a lake is $30°$ and the angle of depression of its reflection in the lake is $60°$. What is the height $\left(\mathrm{m}\right)$ of the cloud above that lake-level?

The angle of elevation of the top of a hill at the foot of a tower is $60°$ and the angle of elevation of the top of the tower from the foot of hill is $30°$. If the tower is $50 \mathrm{m}$ high, then find the height of the hill in metres.

The angle of elevation of the top $B$ of a tower $AB$ from a point $X$ on the ground is $60°$. At a point $Y$, $40 \mathrm{m}$ vertically above $X$, the angle of elevation of the top is $45°$. Find the height of the tower $AB$ and the distance $XB$.