Question

answer this question from points A and B on level ground the angles of elevation of the top of a building are 25° and 37° respectively. if |AB|=57m,calculate, to the nearest metre, the distances of the top of the building from A and B if they are both on the same side of the building

Answers

If you draw the diagram and review your basic trig functions, then if the height is h, it becomes clear that
h cot25° - h cot37° = 57
h = 57/(cot25° - cot37°) = 69.73m
Tan25 = h/x
h =x*Tan25.

Tan37 = h/ (x-57)
h = (x-57)Tan37.

h = x*Tan25 = (x-57)Tan37
x*Tan25 = (x-57)Tan37
x*Tan25 = x*Tan37-57*Tan37
0.467x = 0.754x-43.
X = 150 m. = hor. distance from point A to foot of bldg.
x-57 = 150-57 = 93 m. = hor. distance from point B to foot of bldg.
h = x*Tan25 = 150*Tan25 = 70 m. = ht. of bldg.

sin25 = h/r = 70/r
r = 166 m. = distance from point A to top of bldg.

sin37 = h/r = 70/r
r = 116 m. = distance from point B to top of bldg.


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