Line following two constraints

var p:MovieClip = new MovieClip();

addChild(p);

var ctr:Point = new Point(300,300);

var perimeterPt:Point = new Point();

var rad:int = 200;

var angle:int = 270;

var fac:Number = Math.PI/180;

var t:Timer = new Timer(30,0);

t.addEventListener(TimerEvent.TIMER,drawF);

t.start();

function drawF(e:TimerEvent):void{

    with(p.graphics){

        clear();

        lineStyle(0)

        perimeterPt.x = ctr.x+rad*Math.cos(angle*fac);

        perimeterPt.y = ctr.x+rad*Math.sin(angle*fac);

        moveTo(pivot_mc.x,pivot_mc.y);

        lineTo(perimeterPt.x,perimeterPt.y);

        circle.x = perimeterPt.x;

        circle.y = perimeterPt.y;

        angle++;

    }

}