<svg viewBox="0 0 100 100">
    
    <clipPath id="clip">
      <path d="M 50 0 a 50 50 0 0 1 0 100 50 50 0 0 1 0 -100 v 8 a 42 42 0 0 0 0 84 42 42 0 0 0 0 -84" />
    </clipPath>

    <rect x="0" y="0" width="100" height="100" clip-path="url(#clip)" />
</svg>

svg {
  max-width: 240px;
}

rect {
  fill: orange;
}