<html>
  <head>
    <style>.triangle {  border-color: #000 #fff #fff #fff;  border-style: solid;  border-width: 100px 50px 0 50px;  heigth: 0;  width: 0;}.quadro{width:100px;  height: 100px; background: silver}.round{border-radius:100px;  width:100px;height: 100px;  background:blue}</style>
  </head>
  <body>
    <div class="triangle"></div>
    <div class="quadro">&nbsp;</div>
    <div class="round">&nbsp;</div>
  </body>
</html>