simple up and down svg arrows

by jorgeluis

HTML

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 36 18">
  <polygon class="shape" points="36 18 0 18 18 0 " />
</svg>

<br>
<br>

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 36 18">
  <polygon class="shape" points="0 0 36 0 18 18 " />
</svg>

CSS

.shape {
    fill: black;
}