 Hi and welcome to the session, let's work out the following question. The question says from a building 60 meters high, the angle of depression of the top and bottom of lamp post are 30 degree and 60 degree respectively, find the distance between lamp post and building, also find the difference of height between building and lamp post. So let this be the lamp post and let the height of the lamp post be h meters. Now this is the building 60 meters high. Let us start with the solution to this question. We see that in triangle ABM, since triangle ABM is the right angle triangle, so we can say that tan 60 degree is equal to MB divided by X because we have considered this distance to be equal to X meters. Now tan 60 degree is root 3, so root 3 is equal to 60 divided by X because MB is 60 meters. This implies that X is equal to 60 divided by root 3, now we can multiply the numerator and denominator by root 3 and this gives us 60 root 3 divided by 3 and that is equal to 20 root 3 and that is equal to 34.64 meters. Now we see that MC is equal to BM minus BC, so we can say that MC is equal to 60 minus H because BC is equal to AD that is equal to H. Now in triangle DCM tan 30 degree is equal to MC divided by CD, now tan 30 degree is 1 by root 3, so 1 by root 3 is equal to 60 minus H divided by X or 1 by root 3 is equal to or we can say that 1 by root 3 is equal to 60 minus H divided by 20 root 3 because X is equal to 20 root 3. This implies that 20 root 3 divided by root 3 is equal to 60 minus H, now root 3 gets cancelled with root 3 and this gives us H is equal to 60 minus 20 that is equal to 40. So our answer to this question is that distance between lamp post and building that is X is equal to 34.64 meters, also the difference of height between building and lamp post is 60 minus 40 that is equal to 20 meters, so this is our answer to this question, I hope that you understood the solution and enjoyed the session, have a good day.