Rotation of an ImageLabel from the X and Y of the mouse?

local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()
script.Parent.MouseButton1Down:connect(function()
end)

This is all I really have at the moment, I am trying to minus the center of the ImageLabel (script.Parent, also my friend said to turn the center into a Vector2 but I don't really understand that) from Mouse.X and Mouse.Y and then use math.atan2 to turn it into raidans.

I am trying to do the following :

Click on a so called knob which will follow the mouse until MouseButton1 is released, so the rotation of the ImageLabel will follow the mouse, any ideas on how I can do the following I explained?

##Math Background

Think about this from a trigonometric point of view:

tan(theta) = opp/adj

Therefore:

theta = arctan(opp/adj)

When programing, you'll want to use the function atan2 because it properly handles the divide by 0 case. So now what is opp and adj?

Think of the definition of trigonometric functions, recalling the right angle triangle. You want the angle between the x-axis and hypotenuse, so opp will be the y distance and adj will the the x distance.

To get these distances, subtract the components of the point you are starting at from the components of the point you want to point towards:

opp, adj = y2 - y1, x2 - x1

##Code Snippet

x1, y1 = gui.AbsolutePosition.X, gui.AbsolutePosition.Y
x2, y2 = mouse.X, mouse.Y
angle = math.atan2(y2 - y1, x2 - x1)