<!DOCTYPE html>
<html>
<style>
    .small-box {
        width: 100px;
        height: 100px;
        display: inline-block;
    }
    .large-box {
        width: 200px;
        height: 200px;
        display: inline-block;
    }
</style>    
<body>
    <div>
        <div class="small-box" style="background-color: red;"></div>
        <div class="small-box" style="background-color: green;"></div>
        <div class="small-box" style="background-color: blue;"></div>
    </div>
    <div>
        <div class="large-box" style="background-color: red;"></div>
        <div class="large-box" style="background-color: green;"></div>
        <div class="large-box" style="background-color: blue;"></div>
    </div>
</body>
</html>