高德已知圆心，半径，计算圆弧坐标

 public void addPolylinescircle(LatLng centerpoint, int radius) {
        double r = 6371000.79;
        PolylineOptions options = new PolylineOptions();
        int numpoints = 360;
        double phase = 2 * Math.PI / numpoints;

        //画图
        for (int i = 0; i < numpoints; i++) {
            /**
             * 计算坐标点
             */
            double dx = (radius * Math.cos(i * phase));
            double dy = (radius * Math.sin(i * phase));//乘以1.6 椭圆比例

            /**
             * 转换成经纬度
             */
            double dlng = dx / (r * Math.cos(centerpoint.latitude * Math.PI / 180) * Math.PI / 180);
            double dlat = dy / (r * Math.PI / 180);
            double newlng = centerpoint.longitude + dlng;
            options.add(new LatLng(centerpoint.latitude + dlat, newlng));
        }

        aMap.addPolyline(options.width(10).useGradient(true).setDottedLine(true));

    }