Ideas on how to check if mouse moved in a specific shape

I am making a game where the player has to do some "spells". These spells are made by drawing shapes with the mouse. I have an object that is put on a canvas and moves with the mouse clicking, holding and dragging. It has a trail renderer. The problem is that I don't really know how to know if the player did any spell correctly. Spells are symbols that the player has to draw. For example, drawing the ">" sign top to bottom, triggers an attack spell. I tought that I could detect the angle given by

 float alpha =  Vector2.Angle(lastPoint - currentPoint, Vector2.right)
 // lastPoint is the point from where the mouse started
 // currentPoint is the point where the mouse is now

then check:

 Mathf.abs(alpha - lastAlpha) > 10
 // lastAlpha is 0 at the beggining then when this becomes true:
 lastAlpha = alpha

to detect when the direction was changed. Then, according on some length and x/y distance criteria I could detect if any of the spells was made. But this doesn't really work. I tought that I could save spells as an object:

 class Spell {
    public string name;
    Vector2[] directions;
 }

So for example ">" is { name: "attack", directions: [ new Vector2(40, 20), new Vector2(-40, 20) ] }, meaning that you have to go at least 40 to the right and 20 down, approximately half of x on y and then at least 40 left and 20 down, approximatley half of x on y.

I know this seems hard but maybe there is an easy solution. I would like any help even if it means rethinking the whole system. Thank you.