Avector has an x-component
of -309 m and a y-component
of 187 m.
find the magnitude of the
vector.

Explanation:

The magnitude of a vector v can be found using Pythagorean's theorem.

||v|| = √(vₓ² + vᵧ²)

||v|| = √((-309)² + (187)²)

||v|| ≈ 361

You can find the angle of a vector using trigonometry.

tan θ = vᵧ / vₓ

tan θ = 187 / -309

θ ≈ 149° or θ ≈ 329°

vₓ is negative and vᵧ is positive, so θ must be in the second quadrant.  Therefore, θ ≈ 149°.

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)