What happens when you're attempting to teach from home in California during a coronavirus lockdown during the week that Half Life: Alyx lands? You do both, of course.

Extremely cool teacher Charles Coomber —who works for California's Springs Charter schools, at the Otay Ranch Academy for the Arts — taught a lesson in angle vocabulary from his apartment set within the long-awaited new virtual reality first-person shooter from developer Valve. Half Life: Alyx dropped on Monday, years after the iconic original game was released in 1998, and its sequel in 2006.

Coomber shows you around his balcony, which looks over the game's virtual city. "We are in the middle of a lockdown, so you can see there's not a lot of people on the street," he says, looking out over the landscape, before heading back inside to his prepared lesson written on the apartment windows. Picking up different coloured markers, Coomber proceeds to teach using his VR headset and controllers — wait for the moment of victory when he finally finds the black marker, the most important of all markers.

It's pretty incredible watching the accuracy and detail of physically writing on glass within the world of Valve's game. If you want a quick lesson in complementary and supplementary angles, while checking out a tiny part of Half Life: Alyx, this is it.

Meanwhile, if you want to support Coomber by donating to his classroom fundraiser, here's the link.