小圆环绕大圆

function fn(n) {
return 380 + 100 * Math.sin(n * ((2 * Math.PI) / 7)) - 20;
};
function fm(m) {
return 380 - 100 * Math.cos(m * ((2 * Math.PI) / 7)) - 20;
};
function fg(g) {
div = document.querySelector("#div"+g);
div.style.position = "absolute";
div.style.width = "40px";
div.style.height = "40px"
div.style.background = "brown";
div.style.borderRadius = "20px";
div.style.left = fn(g) + "px"
div.style.top = fm(g) + "px"
};
div = document.querySelector("#div0");
div.style.position = "absolute";
div.style.left = "300px";
div.style.top = "300px";
div.style.width = "160px";
div.style.height = "160px"
div.style.background = "brown";
div.style.borderRadius = "80px";
fg(1);fg(2);fg(3);fg(4);fg(5);fg(6);fg(7);

小圆环绕大圆

原文：http://www.cnblogs.com/YCxiaoyang/p/7208474.html