Refer to the diagram shown below.
The vector has a magnitude of a and a direction of θ degrees south of west.
Use the Pythagorean Theorem to calculate a.
a² = (-530)² + (-200)² = 320900
a = √(320900) = 566.48 mi ≈ 566.5 mi
By definition,
tan θ = (-200)/(-530) = 0.3774
θ = tan⁻¹ 0.3774 = 20.68° ≈ 21°
Answer: about 566.5 mi; 21° south of west.