HTML

<div class="left_arrow">
<div class="arrow"></div>
<div class="body">links</div>
</div>

CSS

.left_arrow {
height:50px;
width:150px;
position:relative;
}
.left_arrow .arrow {
border:25px solid #FFF;
border-right:25px solid #C00;
width:0;
height:0;
overflow:hidden;
margin-left:-25px;
}
.left_arrow .body {
margin:-35px 0 0 25px;
top:15px; left:25px;
height:20px;
background:#C00;
color:white;
text-align:center;
}