This is a port of SASS Angled Edges for Stylus.
Copy file angled-edges.styl to your project and import it
@import 'angled-edges'
Now you can use angled-edge mixin
angled-edge(location, hypotenuse, fill, width=2800, height=100)
The main mixin creates an svg right triangle that is encoded, set as a background image of a pseudo element, and absolutely positioned.