Пример
https://jsfiddle.net/soledar10/85g22ruh/<div class="b-tooltip">
text text text
</div>
.b-tooltip{
background: #fff;
position: relative;
display: inline-block;
padding: 15px;
border: 5px solid #666;
border-radius: 10px;
}
.b-tooltip:before,
.b-tooltip:after{
content: '';
position: absolute; top: 100%;
width: 0;
height: 0;
border-style: solid;
}
.b-tooltip:before{
left: 10px;
border-width: 30px 30px 0 0;
border-color: #666 transparent transparent transparent;
}
.b-tooltip:after{
left: 15px;
border-width: 18px 18px 0 0;
border-color: #fff transparent transparent transparent;
}