var pA:Point=new Point(100,100);

var pB:Point=new Point(300,200);

var dx:Number=pA.x-pB.x;

var dy:Number=pA.y-pB.y;

var dist:Number=Math.sqrt(dx*dx+dy*dy);

//勾股定理

trace(dist);

var p1:Point=new Point(50,50);

var p2:Point=new Point(275,200);

trace(Point.distance(p1,p2));