Question

a plane flies in a straight line path after taking off, and it ends up 210 km farther east and 90.0 km farther north, relative to where it started. What is the plane's displacement?

Answer 1

or the first one use Pythagorean.
distance^2= 210^2 + 90^2
=228.47km, about 230km

For the second use: Inverse-tangent of 90/200
=24.23 degrees, about 24 degrees

Answer 2

Typo 90/200 should read 90/210