Adding radius line from center of circle to point on circle using ArcGIS API for JavaScript?

Question

The following code adds a circle of given radius to the graphics layer on an ArcGIS map. How can i add a line that joins center of the circle to any point on the circle to the graphics layer.

Basically the question is how do i calculate a point on the circle, draw a line that joins the center to the point on the circle and add it to the graphics layer.

 performSearchPoint : function(e) {
 var self = this;
 var radius = $('#radius-distance').val();
 if(radius > 0 && radius < 100000){
 $('#besideMouse').removeClass('hide');
 $('#besideMouse').show();
 var loadingBMint = setInterval(this.loadingBM, 0);
 var searchPointClick = OURAPP.App.Map.on("click",function(evt) {
 loadingBMint = clearInterval(loadingBMint);
 $('#besideMouse').hide();
 var radius = $('#radius-distance').val();
 var units = $("input:radio[name='unitsGroup']:checked").val();
 if (units == "miles"){
 units = "9035"; // if we use GeometryService
 } else {
 units = "9003"; // if we use GeometryService
 }
 //clear only search graphics
 for ( var gr in OURAPP.App.Map.graphics.graphics) {
 if(OURAPP.App.Map.graphics.graphics[gr].infoTemplate != null){
 var template = OURAPP.App.Map.graphics.graphics[gr].infoTemplate;
 if(template != "undefined" || template != null){ 
 if(template.title.trim() == "Search Graphic"){
 OURAPP.App.Map.graphics.remove(OURAPP.App.Map.graphics.graphics[gr]);
 } 
 }}}
 /*do buffer geometry for draw circle and use the circle geometry to get the features*/
 var geoService = new OURAPP.esri.GeometryService("http://XXXX:YYYY/arcgis/rest/services/Utilities/Geometry/GeometryServer");
 var params = new OURAPP.esri.BufferParameters();
 params.geometries = [ evt.mapPoint ];
 params.distances = [ radius ];
 params.unit = units;
 params.bufferSpatialReference = OURAPP.App.Map.spatialReference;
 params.outSpatialReference = new OURAPP.esri.SpatialReference(4326);
 var bufferPolygon = new OURAPP.esri.Polygon;
 bufferPolygon.spatialReference = new OURAPP.esri.SpatialReference(4326);
 geoService.buffer(params,function(geometries) {
 var symbol = new OURAPP.esri.SimpleFillSymbol()
 .setColor(null).outline.setColor("red");
 dojo.forEach(geometries,function(geometry) {
 geometry.spatialReference = new OURAPP.esri.SpatialReference(4326);
 var graphic = new OURAPP.esri.Graphic(geometry,symbol);
 // add name to identify the search graphics
 var template = new OURAPP.esri.InfoTemplate(graphic.geometry);
 template.setTitle("Search Graphic");
 template.setContent("Map Query circle with Radius: " + radius);
 graphic.setInfoTemplate(template); 
 OURAPP.App.Map.graphics.add(graphic);
 bufferPolygon = geometry;
 OURAPP.App.Map.setExtent(graphic.geometry.getExtent().expand(2));
 });
 self.searchType="Distance Search from point";
 self.nameofplace=radius + " "+$("input:radio[name='unitsGroup']:checked").val();
 self.showCount(bufferPolygon);
 });
 searchPointClick.remove();
 });
 }
 },

---

I was able to draw a line and add it to the graphics layer using the following. The [-XX.XXXXXXXXXXXX,YY.YYYYYYYYYYY] is a random point on the map, Now only thing left is to find a point on a circle. So now the question becomes how to find a point which is X miles from a known point(Center of the circle) along the same latitude.

 var lineSymbol = new OURAPP.esri.CartographicLineSymbol(
 OURAPP.esri.CartographicLineSymbol.STYLE_SOLID,
 new OURAPP.esri.Color([255,0,0]), 2,
 OURAPP.esri.CartographicLineSymbol.CAP_SQUARE,
 OURAPP.esri.CartographicLineSymbol.JOIN_MITER, 5
 );
 var lineGeometry = new OURAPP.esri.Polyline; 
 lineGeometry.spatialReference = new OURAPP.esri.SpatialReference(4326);
 lineGeometry.addPath([[evt.mapPoint.getLongitude(),evt.mapPoint.getLatitude()], [-XX.XXXXXXXXXXXX,YY.YYYYYYYYYYY]])
 var lineGraphic = new OURAPP.esri.Graphic(lineGeometry, lineSymbol);
 OURAPP.App.Map.graphics.add(lineGraphic);

Answer 1

This is the best possible one i came up with and its working.

 var lineSymbol = new OURAPP.esri.CartographicLineSymbol(
 OURAPP.esri.CartographicLineSymbol.STYLE_SOLID,
 new OURAPP.esri.Color([255,0,0]), 2,
 OURAPP.esri.CartographicLineSymbol.CAP_SQUARE,
 OURAPP.esri.CartographicLineSymbol.JOIN_MITER, 5
 );
 var radiusInMeters; 
 if (selectedUnit == "miles"){
 radiusInMeters = radius*1609.34; //have to convert it to meters. 
 } else {
 radiusInMeters = radius*0.3048; //have to convert it to meters. 
 }
 // Calculate the new map point on the circle.
 var radians = Math.PI/180;
 var ltLong = OURAPP.esri.webMercatorUtils.xyToLngLat(evt.mapPoint.x + radiusInMeters*Math.cos(radians), evt.mapPoint.y + radiusInMeters*Math.sin(radians));
 // Calculate the new map point on the circle. 
 var lineGeometry = new OURAPP.esri.Polyline; 
 lineGeometry.spatialReference = new OURAPP.esri.SpatialReference(4326);
 lineGeometry.addPath([[evt.mapPoint.getLongitude(),evt.mapPoint.getLatitude()], ltLong]);
 var lineGraphic = new OURAPP.esri.Graphic(lineGeometry, lineSymbol);