How to find degrees using coordinates (x,y)

Question

I want to find degrees:
x1 = 0
y1 = 0
x2 = 30
y2 = 40

y
| (40,30)
| /
| /
| ? /
| /
|/_________________x

What is the degrees of this line and how to find this?

Answer 1

Do you know sin, cos, tan and how to apply them in a right angled triangle? If yes, could you use the point, the origin and one of the axes to construct a right angled triangle? What would be the length of its sides? (Hint: you only need two sides plus the appropriate trigonometric function)

Answer 2

Also, „what is the degrees of this line“ is not very specific. Which angle do you mean?