.yukaridiv, .asagidiv, .soldiv, .sagdiv{ width:600px;
min-height:40px; /*min height of DIV should be set to at least 2x the width of the arrow*/
background: black;
color:white;
padding:5px;
position:relative;
word-wrap:break-word;
-moz-border-radius:5px; /*add some nice CSS3 round corners*/
-webkit-border-radius:5px;
border-radius:5px;
margin-bottom:2em;
}
.yukaridiv:after{ /*arrow added to uparrowdiv DIV*/
content:'';
display:block;
position:absolute;
top:-20px; /*should be set to -border-width x 2 */
left:30px;
width:0;
height:0;
border-color: transparent transparent black transparent; /*border color should be same as div div background color*/
border-style: solid;
border-width: 10px;
}
.asagidiv:after{ /*arrow added to downarrowdiv DIV*/
content:'';
display:block;
position:absolute;
top:100%; /*should be set to 100% */
left:30px;
width:0;
height:0;
border-color: black transparent transparent transparent; /*border color should be same as div div background color*/
border-style: solid;
border-width: 10px;
}
.soldiv:after{ /*arrow added to leftarrowdiv DIV*/
content:'';
display:block;
position:absolute;
top:10px;
left:-20px; /*should be set to -border-width x 2 */
width:0;
height:0;
border-color: transparent black transparent transparent; /*border color should be same as div div background color*/
border-style: solid;
border-width: 10px;
}
.sagdiv:after{ /*arrow added to rightarrowdiv DIV*/
content:'';
display:block;
position:absolute;
top:10px;
left:100%; /*should be set to 100% */
width:0;
height:0;
border-color: transparent transparent transparent black; /*border color should be same as div div background color*/
border-style: solid;
border-width: 10px;
}

İşaretleme kısmı

<div class="yukaridiv">
This is a test
</div>
<div class="asagidiv">
This is a test
</div>
<div class="soldiv">
This is a test
</div>
<div class="sagdiv">
This is a test
</div>