How do I find the magnitude and direction angle for vector <-5,12>

(Assuming the one co-ordinate is zero), make a triangle with points (0,0), (-5, 12) (-5, 0) [the x-axis].
Find the value of the hypotenuse for the value of the magnitude (a^2 = b^2 + c^2).
Find the slope to fnd the dirrection angle (rise divided by run).

- Not by Tman, by Tman's brother-in-law.