let x = 100 // center x
let y = 50 // center y
let r = 50 // radius
let a = 0 // angle (from 0 to Math.PI * 2)
function rotate(a) {
let px = x + r * Math.cos(a);
let py = y + r * Math.sin(a);
console.log( px, py );
}
setInterval(function() {
a = (a + Math.PI / 360) % (Math.PI * 2);
rotate(a);
}, 5);