The total distance traveled by signal is s.
So that the distance between Belem (or Quito) to satellite iss / 2
.
Therefore we can write
   s / 2 = √ [ (h)2 + (d /
2)2 ]
                             =
√ [ (3.61 x 107)2 + (3.87x 106 /
2)2 ]
                             =
3.615 x 107 m
        ==>     Â
s = 7.23 x107 m
The time taken by electromagnetic wave to travel a totaldistance s
is
                  t
= s / c
                    =
7.23 x 107 / 3 x 108
   = 0.241 sec
