SVG file conversion to Inkscape

I am following Mozilla’s SVG tutorial, and I have been adding several “demo.svg” files to a folder in my file editor. Many of these files are able to convert over to my Inkscape app, but one of my “demo.svg” files will not convert. On the “Fills and Strokes” portion of the SVG tutorial (https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Fills_and_Strokes), I have copied the code for the “stroke-linejoin” example:

<?xml version="1.0" standalone="no"?>
<svg width="160" height="280" xmlns="http://www.w3.org/2000/svg" version="1.1">
  <polyline points="40 60 80 20 120 60" stroke="black" stroke-width="20"
      stroke-linecap="butt" fill="none" stroke-linejoin="miter"/>
  
  <polyline points="40 140 80 100 120 140" stroke="black" stroke-width="20"
      stroke-linecap="round" fill="none" stroke-linejoin="round"/>
  
  <polyline points="40 220 80 180 120 220" stroke="black" stroke-width="20"
      stroke-linecap="square" fill="none" stroke-linejoin="bevel"/>
</svg>

But this code will not convert over to Inkscape and create the graphic from the code. I’ve tried changing the parameters of the “width” and the “height”, and the “points” parameters but I still can’t get a graphic in Inkscape. What am I missing?

Well, I answered my own question. I converted the SVG file to an HTML file, and now I can open the graphic in my browser and it works!