svg half circle shape
<svg version="1.1" height="200px" width="200px" xmlns="https://www.w3.org/2000/svg" >
<clipPath id="cut-off-bottom">
<rect x="0" y="0" width="200" height="100" />
</clipPath>
<circle cx="100" cy="100" r="100" clip-path="url(#cut-off-bottom)" />
</svg>