For this problem, we are given the two components of a certain vector. We need to determine the magnitude and angle of this vector.
Let's draw the situation to better understand the problem:
We can create a right triangle with the two components and the vector. We can determine the value of R by using Pythagora's theorem:

The value of R is 8.434.
Now we need to determine theta, for that, we can use the sine relation, as shown below:

The value of the angle is equal to -22.27º