<svg width="150px" height="150px" viewBox="0 0 150 150">
  <g style="stroke: black; fill: none;">
    <!-- single line -->
    <path d="M 10 10 L 100 10"/>
    <!-- a right angle -->
    <path d="M 10, 20  L 100, 20  L  100,50"/>
    <!-- two thirty-degree angles -->
    <path d="M 40 60 L 10, 60 L 40 42.68 M 60, 60 L 90 60 L 60, 42.68"/>
  </g>
  <g style="stroke: gray; stroke-width: 8; fill: none;">
    <!-- 4つの直線で描かれる矩形 -->
    <path d="M 10 110 L 40 110 L 40 130 L 10 130 L 10 110"/>
    <!-- closepathを使って描かれる矩形 -->
    <path d="M 60 110 L 90 110 L 90 130 L 60 130 Z"/>
  </g>
</svg>