Question
when viewed from a point P, due north of a tall building, the angle of elevation of the top of the building is 40 degree ; when viewed from a point Q due east of the building, the angle of elevation is 35 degree. If the distance PQ is 120m, find the height of the building.
Answers
Steve
Let's set up some labels.
T = top of building
B = bottom of building
y = BP
x = BQ
If the building has height h, then
h/x = tan 40°
h/y = tan 35°
so, x tan 40° = y tan 35°
x^2+y^2 = 120^2
solving that, we get
x = 76.88
y = 92.13
h = 64.5
T = top of building
B = bottom of building
y = BP
x = BQ
If the building has height h, then
h/x = tan 40°
h/y = tan 35°
so, x tan 40° = y tan 35°
x^2+y^2 = 120^2
solving that, we get
x = 76.88
y = 92.13
h = 64.5
somay
steve you are perfectly crrct. Thank you sir