JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://d3js.org/d3.v2.min.js"></script>
Click and drag the small circles to rotate and resize.

JavaScript

var w = 400,
    h = 400,
    data = {
        x: 150,
        y: 100,
        rx: 100,
        ry: 50,
        angle: 0
    };

// Returns radians
function angleBetweenPoints(p1, p2) {
    if (p1[0] == p2[0] && p1[1] == p2[1])
        return Math.PI / 2;
    else
        return Math.atan2(p2[1] - p1[1], p2[0] - p1[0]);
}

function distanceBetweenPoints(p1, p2) {
    return Math.sqrt(Math.pow(p2[1] - p1[1], 2) + Math.pow(p2[0] - p1[0], 2));
}

var svg = d3.select("body")
            .append("svg")
            .attr("width", 400)
            .attr("height", 300);

var group = svg.append("svg:g");

var handles = group.selectAll("circle")
        .data([
            {x:data.x, y:data.y + data.ry, name:"n"},
            {x:data.x + data.rx, y:data.y, name:"e"},
            {x:data.x, y:data.y - data.ry, name:"s"},
            {x:data.x - data.rx, y:data.y, name:"w"}
        ], function (d) { return d.name; })
        .enter()
        .append("svg:circle")
        .attr("cx", function (d) { return d.x; })
        .attr("cy", function (d) { return d.y; })
        .attr("r", 6.5)
        .call(d3.behavior.drag()
            .on("drag", function (d) {
                // Resizing
                var exy = [d3.event.x, d3.event.y],
                    dxy = [data.x, data.y],
                    dist = distanceBetweenPoints(exy, dxy),
                    angle = angleBetweenPoints(dxy, exy);
                switch(d.name) {
                    case "e":
                    case "w":
                        data.rx = dist;
                        break;
                    case "s":
                    case "n":
                        data.ry = dist;
                        angle += Math.PI/2;
                        break;
                };
                data.angle = angle;
                update();
            })
        );

var ellipse = group.append("svg:ellipse");

function update() {
    ellipse
        .attr("cx", data.x)
        .attr("cy", data.y)
       ...