简单的css小三角

/*css style */   
    #up {                                        
		width:0px;
		height:0px;
		border-bottom:10px solid  #89b007;
		border-left:10px solid #fff;
		border-right:10px solid #fff;
		
	}
	#down {                          
	    width:0px;
		height:0px;
		border-top:10px solid  #89b007;
		border-left:10px solid #fff;
		border-right:10px solid #fff;	
		
	}
		#left {
	    width:0px;
		height:0px;
		line-height:0px;             /*解决ie出现梯形问题*/
		border-right:10px solid  #89b007;
		border-top:10px solid #fff;
		border-bottom:10px solid #fff;	
		
	}
		#right {
	    width:0px;
		height:0px;
		line-height:0px;             /*解决ie出现梯形问题*/
		border-left:10px solid  #89b007;
		border-top:10px solid #fff;
		border-bottom:10px solid #fff;	
		
	}
	#trapezoid {                        
		width:7px;
		height:15px;
		border-bottom:10px solid  #89b007;
		border-left:10px solid #fff;
		border-right:10px solid #fff;
		
	}