createCanvas(600, 600);

}

​

function draw() {

  background(0);

  stroke(255);

  noFill();

  strokeWeight(3);

​

  line(mouseX, mouseY, 150, 450);

  line(mouseX, mouseY, 450, 450);

​

  var m1 = (mouseY - 450) / (mouseX - 150);

  var m2 = (mouseY - 450) / (mouseX - 450);

  var dist1 = dist(mouseX, mouseY, 150, 450);

  var dist2 = dist(mouseX, mouseY, 450, 450);

  let a;

  let deg;

​

  if (m1 * m2 == -1) a = PI / 2;

  //acutes only

  //else a = atan(abs((m1-m2)/(1+m1*m2)));

  else a = acos((Math.pow(dist1, 2) + Math.pow(dist2, 2) - Math.pow(300, 2)) / (2 * dist1 * dist2));

  deg = a / PI * 180;

​

  fill("yellow");

  noStroke();

  text("Angle: " + round(deg, 3), mouseX - 30, mouseY - 10);

​

​

}