Top of tower to ground level where cell phone user is standing 5 miles away is 120 + 800 = 920 feet.
Where did 800 feet come from?
Well, 1200 - height where cell phone user is standing.
I get 1200 - 400 = 800.
Let x = angle of depression.
tan x = 920/5
arctan[tan x ] = arctan(920/5)
x = 89.69°
Yes?
