Finding the angle between 2 clicked points

Questions & Answers
1

I am trying to find the angle between two clicked points, for example. I click down at one point and drag to the next. I can find the x/y coordinates for both points but how do i get the angle between them to ultimatly fire a projectile at that angle?

3

Well,
you have your x and y coordinates from your mouse clicks you said.

Store the coordinates of your clicks and calculates the distance between them , you have found the hypotenuse (hyp) of your triangle. With

hyp = Vector2.Distance(click1,click2);

Now with

xtot =click.x - click1.x;

you get the adjacent side.

Now with

angle = Mathf.Acos(xtot/hyp);

you have your angle.

Is that what you need?

2

Are you sure you need that expressed as an angle? I would use vectors to fire a projectile. You get direction vector simply by subtracting first positions from the second position vector.
If you go with vectors, you can still get an angle from it, but as Jean Fabre mentioned, you need a reference vector (the one that you consider to be at 0 degrees).