This technique uses CSS clip-path to clip the image but has a fallback using pseudo elements for older browsers.
It is only intended for use on full width elements as it uses the vw unit to calulate the angle.
Once you have downloaded the code, run the commands below to view the demo site.
$ npm install
$ gulp serve
You can also import angled-edges.scss into your own project directly and use the classes already setup or use the mixin in your own classes.
Inspired by Kilian Valkhof and Viget
Image from Wikimedia Commons