posted by Jon .
An airplane has a velocity of 454 km/h relative to the moving air. At the same time, a wind blows northward with a speed of 99 km/h relative to earth. The airplane is moving in an easterly direction relative to earth. Find the speed of the airplane to relative to earth.
So, i used pythagorean theorem so square root of 454 squared plus the square root of 99 squared.. and i didn't get the right answer. Can someone explain this problem to me please?