Respuesta :

Use Pythagoras theorem 
(h+r)^2 = r^2 + d^2
d^2 = h^2 + 2hr +r^2 - r^2
 d^2    = h^2 + 2hr

d^2 =  5^2 + 7200^2 =  51840025
d = sqrt 51840025 = 7200.001736