Two men on either side of the cliff, $80 \mathrm{m}$ high, observe the angle of elevation of the top of the cliff to be $30°$ and $60°$ respectively. Find the distance between the two men in metres, rounded off to one decimal place. [Take $\sqrt{3}=1.732$](Write only the numeral values without units)

Find the angle of elevation (in degrees) of the sun (sun's altitude) when the length of the shadow of a vertical pole is equal to its height.

An aeroplane is flying at a height of $210 \mathrm{m}$. Flying at this height at some instant the angles of depression of two points in a line in opposite directions on both the banks of the river are $45°$ and $60°$. Find the width of the river in metres. 

(Use $\sqrt{3}=1.732$).

The angle of elevation of the top of a chimney from the top of the tower is $60°$ and the angle of depression of the foot of the chimney from the top of the tower is $30°$. If the height of the tower is $40$, find the height of the chimney. According to pollution control norms, the minimum height of a smoke emitting chimney should be $100 \mathrm{m}$. State if the height of above mentioned chimney meets the pollution norms.

The horizontal distance between the two poles is $15 \mathrm{m}$. The angle of depression of the top of the first pole as seen from the top of the second pole is $30°$. If the height of the second pole is $24 \mathrm{m}$, find the height of the first pole in metres. $(\sqrt{3}=1.732)$(Write only the numeral values without units correct upto 2 decimal places)

The angle of depression of two ships from the top of a light house and on the same side of it are found to be $45°$ and $30°$ respectively. If the ships are $200 \mathrm{m}$ apart, find the height of the light house in metres. (Write only the numeral values without units)[Take $\sqrt{3}=1.732$]

The angles of elevation of the top of a tower from two points at a distance of $4 \mathrm{m}$ and $9 \mathrm{m}$ from the base of the tower and in the same straight line with it are complementary. Prove that the height of the tower is $6 \mathrm{m}.$