Question 475353
your equation is:
D = 1.2 * sqrt(h)
D is in miles
h is in feet.
Solving this equation for h, you get:
h =(D/1.2)^2
you are correct on that.
In 2B, h = 14110 which means you can see 1.2 * sqrt(14110) = 142.5 miles.
If you want to test your formula for h, then use that formula to get back to the height given the distance.
That formula becomes:
h = (D/1.2)^2 which becomes (142.5426252/1.2)^2 which becomes 14110.
In 2C, you are asked if you can see Denver, presumably from Pike's Peak.  Since you can see 142.5 miles to the horizon from Pike's Peak, then you should have no problem seeing Denver which is only 70 miles away.
In 2D, you are given that h = 20320.
plug that in you equation for D and you get D = 1.2 * sqrt(20320) which equals 171.0578849 miles which rounds to 171 miles.
Since 171 miles is greater than 120 miles, you should easily be able to see Fairbanks which is only 120 miles away.