The angles of elevation of the top of a tower from the top and foot of a pole are respectively 30$$^\circ$$ and 45$$^\circ$$. If h_T is the height of the tower and h_P is the height of the pole, then which of the following are correct?

1. $${{2{h_P}{h_T}} \over {3 + \sqrt 3 }} = h_P^2$$

2. $${{{h_T} - {h_P}} \over {\sqrt 3 + 1}} = {{{h_P}} \over 2}$$

3. $${{2({h_P} + {h_T})} \over {{h_P}}} = 4 + \sqrt 3 $$

Select the correct answer using the code given below.

From the top of a lighthouse, 100 m high, the angle of depression of a boat is $${\tan ^{ - 1}}\left( {{5 \over {12}}} \right)$$. What is the distance between the boat and the lighthouse?

A balloon is directly above one end of a bridge. The angle of depression of the other end of the bridge from the balloon is 48$$^\circ$$. If the height of the balloon above the bridge is 122m, then what is the length of the bridge?

The top of a hill observed from the top and bottom of a building of height h is at angles of elevation $${\pi \over 6}$$ and $${\pi \over 3}$$ respectively. What is the height of the hill?