[thethirdchild]

есть код

function  Shape () {
	this.constructor.name = Shape;
}
Shape.prototype = {
 getPerimeter: function () {
			   if ( this.constructor == Shape ) throw Error( "Forbidden" );
			   var p = 0;
			   for ( var i = 0; i < this.sides.length; i++) {
			    p += this.sides[i];
			   }
			   return p;
			  },
				
 getSquare: function () { 
   	         if ( this.constructor == Shape ) throw Error( "Forbidden" ); 
		    },

 getType: function () { 
		   if ( this.constructor == Shape ) throw Error( "Forbidden" );
		   return name;
		  }	
}

Shape.prototype.constructor = Shape;	//иначе Object() !!!!
			
var Triangle;			
(function () {
 Triangle = function ( a, b, c ) {

  this.sides = [ a, b, c ];
  
 }

 Triangle.prototype = new Shape();
 Triangle.prototype.constructor = Triangle;
 Triangle.prototype.getSquare = function () {
							     var p = this.getPerimeter()/2;
								 var S = Math.sqrt( p * ( p - this.sides[0] ) * ( p - this.sides[1] ) * ( p - this.sides[2] ) );
								 return Math.floor( S );
							    }								
 })();
 var t = new  Triangle ( 10, 15, 20 );

как мне получить тип обекта t и вывести его куданить ( скажем в алерт тот, не суть )