First you will need to find the lateral idea which is
2(15) (3.14) (4)
-multiply them together
Then you will need to find the base.
-3.14x15x4
Then find the surface area
-answer from lateral area and 2(-answer from base-)
Add that and that is ur answer
plane 1 travels 395 miles in 1 hour
plane 2 travels 422 miles in 1 hour
together, they travel (395+422) 817 miles in 1 hour
to have 2451 miles between then, they'd need to travel

so in 3 hours, they'll be 2451 miles apart
The answer is 0.04444... or 2/45. Whichever is more useful to you.