# SVG, <s>562</s> <s>540</s> <s>520</s> 504 bytes
This is my first time golfing SVG (or any markup, in fact); be gentle!
The assumed viewing environment is an SVG-capable web browser with anything like a typical window size. I tested it in Firefox 50 and in Chrome 55.
The `viewBox` is necessary to meet the 100-pixel requirement (blowing up all measurements by a factor of 4 would also work but would take 8 more bytes, if I have counted correctly). Incidentally, it is possible to save another byte by removing the space in `0 -5` in the `viewBox` value, but Firefox won't accept this as valid (whereas Chrome will).
The aspect ratio is 1:1 instead of the true 0.866:1. I'm not sure exactly how the "factor of 2" rule is meant to be interpreted (I think it means that exaggeration as extreme as 0.433:1 or 1.732:1 is acceptable), but I'm pretty sure this meets the requirement anyway.
## SVG
<!-- language: lang-xml -->
<svg xmlns="http://www.w3.org/2000/svg"
xmlns:l="http://www.w3.org/1999/xlink"
viewBox="0 -5 26 26"><style>#b{fill:red}#c{fill:blue}</style><g
id="a"><path d="m7,9H3V5h6z"/><g
id="f"><path id="b" d="m9,5H3V1h4z"/><path id="c" d="m3,1l2,4L3,9l-2-4z"/></g></g><use
l:href="#a" x="3" y="6"/><use
l:href="#e" x="12"/><g
id="e"><use l:href="#a" x="-6" y="12"/><use l:href="#a" x="-12" y="12"/></g><use
l:href="#a" x="-9" y="6"/><use
l:href="#a" x="-6"/><use
l:href="#a" x="-3" y="-6"/><use
l:href="#f"/></svg>
## Result
[![A PNG rendering of the above SVG code for Reutersvärd's Triangle][1]][1]
[1]: https://i.sstatic.net/CxYA6.png