The x component of vector A is -25 m and the y component is 40m

Question

a) what is the magnitude of vector A

b)What is the angle between the direction of vector A and the positive direction of x?

I got a) as 47.16m
by for b) I am having trouble I should be getting 122 degrees for the angle but I got -57.9 degrees which is wrong according to the book.

The angle will depend on how it is measured. Measuring from the y axis, the angle is

arctan(-25/40)

Now notice this from the above: I have indicated theta is the angle between y and the vector, NOT x and the vector.
To get the angle from the xaxis, add 90.