I'm trying to find the coords of the red point in the image, I have the mouse coords, the initial point and the radio but I don't know how to find the coords of the red point.
I am using JavaScript and canvas.
To find the angle:
var diffX = mouseX - centerX;
var diffY = mouseY - centerY;
var angle = Math.atan2(diffY, diffX);
To find the new point use that angle with radius:
var x = cx + radius * Math.cos(angle);
var y = cy + radius * Math.sin(angle);