M-Physics Help Please (Magnitude)?

Question

A bird flies 4.2 km due west and then 1.6 km due north.

What is the magnitude of the bird's displacement?

Answer 1

Think of East/West as the x-axis and North/South as the y-axis.

Then think of it's motion as a right-triangle, with x = -4.2, and y = 1.6.

The displacement (d) will be the hypotenuse of the right-triangle.

Use the Pythagorean Theorem to solve:

x^2 + y^2 = d^2

The result (d) is the magnitude of said displacement.