A ranger in fire tower A spots a fire at a direction of 40 d
Solution
Let the distance between the tower A and the fire be L and distance between tower B and fire be D.
Then, we know that the horizontal distance is 28 miles.
by Geometry,
Lcos40o - Dcos116o = 28
=> 0.766L + 0.438D = 28 .......................[1]
Also, since tower A and tower B are directly in the east - west direction, therefore their vertical component of distances must match.
[this is because tower A does not bear any angle with tower B]
so, Lsin40o = Dsin114o ..........................[2]
=> D = 0.7036L
substitute this in equation [1]
this will give : 0.766L + 0.438[0.7036L] = 28
0.766L + 0.3084L = 28
=> L = 26.06 miles.
so the fire is at a distance of 26.06 miles from tower A.
2] Use Pythagoras\' theorem
a2 + b2 = c2
here, a = 295 ft and c = 648 ft
so (295)2 + b2 = (648)2
=> b = [467856 - 87025]1/2 = 576.96 ft = 577 ft.
So the height of the tower is 577 ft.
