title: How to find coords from angle in a circle
body: <p>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.</p>
  
  <p><img src="https://i.stack.imgur.com/SZzEQ.png" alt="enter image description here"></p>
  
  <p>I am using JavaScript and canvas.</p>