#first {
	float:left;
	width:200px;
	border:10px dashed #f00;
	color:#c00;
	background-color:#fcc;
}
#second {
	float:left;
	width:340px;
	border:10px dotted #0f0;
	color:#0c0;
	background-color:#cfc;
}
#third {
	width:200px;
	float:right;
	border:10px dotted #00f;
	color:#00c;
	background-color:#ccf;
}
100px
100px and 10px border
120px