<!DOCTYPE html>
<html>

  <head>
    <link rel="stylesheet" href="style.css">
    <script src="script.js"></script>
  </head>

  <body>
    <img src="https://goo.gl/MoeMWp" alt="" class="Icon Icon--small" />
    <img src="https://goo.gl/MoeMWp" alt="" class="Icon" />
    <img src="https://goo.gl/MoeMWp" alt="" class="Icon Icon--large" />
  </body>

</html>
.Icon {
  width: 2em;
  height: 2em;
}

.Icon--small {
  width: 1em;
  height: 1em;
}

.Icon--large {
  width: 3em;
  height: 3em;
}