var cube = function (e,f,g) { 
	var that= {};
	that.s1 = e;
	that.s2= f;
	that.s3 =g;
	that.s4= vect(f,sommec(e,g));
	var areteNormale= prodVectc(vectc(f,e),vectc(f,g));
	var a= norme(e,f); 
	areteNormale= prodRc(1/a,areteNormale);
	that.s5= somme(e,areteNormale);
	that.s6= somme(f,areteNormale);
	that.s7= somme(g,areteNormale);
	that.s8= somme(that.s4,areteNormale);
	
	that.getS4 = function () {
		return that.s4;
	}
	
	that.getS5 = function () {
		return that.s5;
	}
	
	that.getS6 = function () {
		return that.s6;
	}
	
	that.getS7 = function () {
		return that.s7;
	}
	
	that.getS8 = function () {
		return that.s8;
	}
	
	Polygon(that.s1.name+","+that.s2.name+","+that.s3.name+","+that.s4.name);
	Polygon(that.s1.name+","+that.s2.name+","+that.s6.name+","+that.s5.name);
	Polygon(that.s2.name+","+that.s3.name+","+that.s7.name+","+that.s6.name);
	Polygon(that.s3.name+","+that.s4.name+","+that.s8.name+","+that.s7.name);
	Polygon(that.s4.name+","+that.s1.name+","+that.s5.name+","+that.s8.name);
	Polygon(that.s5.name+","+that.s6.name+","+that.s7.name+","+that.s8.name);
	
	return that;
};