CSS3 Tutorial: creating shapes

With CSS3 we are also able to create various geometric shapes, like triangles, parallelograms, stars, circles, ovals, etc. Previously we needed Javascript for this kind of trickery, but no more. In the examples below I constructed various shapes, using only CSS3 and HTML.

.cirkel { 
    width: 140px;
    height: 140px;
    background: red; 
    -moz-border-radius: 70px; 
    -webkit-border-radius: 70px; 
    border-radius: 70px;