Given that the diagram shows the location of John and Mark in relationship to the top of the building labeled A, then:
a]
∠4 is the angle of elevation as seen by Mark from his location. It is the angle between the horizontal and the line from the object to the observer's eyes.
b]
∠3 is the angle of depression and it is congruent to the angle 5, which is the angle of elevation as seen by John from his location.
Pull terms out from under the radical, assuming positive real numbers.
56
Have a good one :)
The equation of a circle:

where
(h, k) - the coordinates of a center
r - the radius
We have:


Okay so to figure out this problem you need to say 5/1 times 3/4 which equals 15/4 We know that we cant have an improper fraction so we divide this and it equals 3