Edit in JSFiddle

<div class="box-set">
  <figure class="box">Блок 1</figure>
  <figure class="box">Блок 2</figure>
  <figure class="box">Блок 3</figure>
</div>

body {
  color: #fff;
  font: 600 14px/24px "Open Sans", "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", Sans-Serif;
}
.box-set,
.box {
  border-radius: 6px;
}
.box-set {
  background: #eaeaed;
  overflow: auto;
}
.box {
  background: #2db34a;
  float: left;
  margin: 1.858736059%;
  padding: 20px 0;
  text-align: center;
  width: 29.615861214%;
}