put one div inside another!

Question

I have a div and I need to put two Ivs inside of it,the problem is that the div in which the others will be inserted,is not tall enough for that. How can I make this position?

follow the codes below!

.leftside {
    width: 750px;
    float: left;
}

.rightside {
    width: 278px;
    min-height: 300px;
    float: right;
    margin-left: 12px;
}

.widget {
    border: 1px solid #ccc;
    background-color: #fff;
    margin-bottom: 10px;
    border-radius: 2px;
}

.widget_titulo {
    height: 30px;
    line-height: 30px;
    background-color: #ddd;
    border-bottom: 1px solid #ccc;
    padding-left: 5px;
    font-size: 14px;
}

.widget_conteudo {
    text-align: center;
    padding-top: 5px;
    padding-bottom: 5px;
}

.noticia_item {
    font-size: 14px;
    margin: 0px 10px;
    padding: 10px 0px;
    text-align: left;
    border-bottom: 1px solid #ccc;
}

.noticia_item a {
    text-decoration: none;
    color: #000;
}

.slideshow {
    height: 335px;
    overflow: hidden;
    margin-bottom: 20px;
}

.slideshow_area {
    width: 10000px;
    height: 335px;
    transition: all 1s;
}

.slide {
    height: 335px;
    float: left;
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
}

.slide img {
    height: 335px;
    width: 750px;
}

.slideinfo {
    position: relative;
    top: -70px;
    height: 70px;
    background-image: url('../images/slideshow_bg.png');
    background-size: auto 70px;
    z-index: 10000;
}

.slideinfo_titulo {
    font-size: 20px;
    color: #fff;
    padding-top: 20px;
    margin-left: 20px;
}

.slideinfo_subtitulo {
    font-size: 13px;
    margin-left: 20px;
    color: #fff;
}

.bolls {
    position: absolute;
    width: 200px;
    height: 15px;
    margin-left: 10px;
    padding-top: 10px;
}

.boll {
    width: 15px;
    height: 15px;
    float: left;
    margin-right: 5px;
    cursor: pointer;
    background-color: #d0d1cc;
    border-radius: 10px;
}

.noticiaarea1 {
    width: 430px;
    height: 420px;
    float: left;
    background-color: #ddd;
}

.noticiaarea2 {
    width: 315px;
    height: 420px;
    float: right;
    background-color: #ccc;
}

           <div class="widget">
            <div class="widget_titulo">NOTÍCIAS</div>
            <div class="widget_conteudo">
                <div class="noticiaarea1">

                </div>
                <div class="noticiaarea2">

                </div>
                <div class="clear:both"></div>
             </div>

Answer 1

Dude I see an HTML error in your clear there should be a class <div class="clear"></div> or if you prefer to use inline even add style instead of class <div style="clear: both;"></div>

.leftside {
    width: 750px;
    float: left;
}

.rightside {
    width: 278px;
    min-height: 300px;
    float: right;
    margin-left: 12px;
}

.widget {
    border: 1px solid #ccc;
    background-color: #fff;
    margin-bottom: 10px;
    border-radius: 2px;
}

.widget_titulo {
    height: 30px;
    line-height: 30px;
    background-color: #ddd;
    border-bottom: 1px solid #ccc;
    padding-left: 5px;
    font-size: 14px;
}

.widget_conteudo {
    text-align: center;
    padding-top: 5px;
    padding-bottom: 5px;
}

.noticia_item {
    font-size: 14px;
    margin: 0px 10px;
    padding: 10px 0px;
    text-align: left;
    border-bottom: 1px solid #ccc;
}

.noticia_item a {
    text-decoration: none;
    color: #000;
}

.slideshow {
    height: 335px;
    overflow: hidden;
    margin-bottom: 20px;
}

.slideshow_area {
    width: 10000px;
    height: 335px;
    transition: all 1s;
}

.slide {
    height: 335px;
    float: left;
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
}

.slide img {
    height: 335px;
    width: 750px;
}

.slideinfo {
    position: relative;
    top: -70px;
    height: 70px;
    background-image: url('../images/slideshow_bg.png');
    background-size: auto 70px;
    z-index: 10000;
}

.slideinfo_titulo {
    font-size: 20px;
    color: #fff;
    padding-top: 20px;
    margin-left: 20px;
}

.slideinfo_subtitulo {
    font-size: 13px;
    margin-left: 20px;
    color: #fff;
}

.bolls {
    position: absolute;
    width: 200px;
    height: 15px;
    margin-left: 10px;
    padding-top: 10px;
}

.boll {
    width: 15px;
    height: 15px;
    float: left;
    margin-right: 5px;
    cursor: pointer;
    background-color: #d0d1cc;
    border-radius: 10px;
}

.noticiaarea1 {
    width: 430px;
    height: 420px;
    float: left;
    background-color: #ddd;
}

.noticiaarea2 {
    width: 315px;
    height: 420px;
    float: right;
    background-color: #ccc;
}
.clear {
    clear: both;
}

<div class="widget">
     <div class="widget_titulo">NOTÍCIAS</div>
     <div class="widget_conteudo">
         <div class="noticiaarea1">

         </div>
         <div class="noticiaarea2">

         </div>
         <div class="clear"></div>
     </div>
</div>