It seems like your question is lacking some specifics. However, here's a straightforward solution:
UPDATE: Oops, I forgot to include my positioning details.
HTML
<div class="c1"></div>
<div class="c2"></div>
<div class="c3"></div>
CSS
html, body {
height: 100%;
position: relative;
}
.c1 {
height: 100%;
width: 33.3%;
position: absolute;
left: 0;
top: 0;
}
.c2 {
height: 100%;
width: 33.3%;
position: absolute;
left: 33.3%;
top: 0;
}
.c3 {
height: 100%;
width: 33.3%;
position: absolute;
left: 66.6%;
top: 0;
}
Please note that there are multiple approaches to achieve this layout. You can utilize floats, inline-block, and more.