If the point (-5, -12) is a point on the terminal side of an angle in standard position, how do you find the radius of the circle?
If I got the idea of terminal side of the angle right, you could use Pitagora's Theorem to find the radius.
From the picture:
You can use Pitagora's Theorem applied to the triangle
Which is the radius.
Using trigonometry (in particular inverse trigonometric functions) you can also find the angle that the radius