Find out more about Jane Street’s programmes running across the world: https://bit.ly/sum-janestreet-programs

Including the WiSE course which is open to self-identifying women and gender-expansive university students and incoming students: https://www.janestreet.com/join-jane-street/programs-and-events/wise/

Check out KangarooPhysics’ original gif showing the cross-section through the packing arrangment: https://x.com/kangaroophysics/status/1491858072251342850?s=46&t=EVDbN01K_p7T27Gd23R0bw And Daniel Piker’s amazing 3D model: https://sketchfab.com/3d-models/rod-packing-7directions-2-e56a6e899b2b4ef4bb458c66343363e4 More detail on rod packing in this paper: https://journals.iucr.org/paper?S010876730001151X

If you want to watch the extended cut, with every excruciating, pencil-pushing moment included, head over to this video on the second channel: https://www.youtube.com/watch?v=EsBqeGtThW8

You can also watch the original "How to build a Hexastix in 72 easy steps" if you just want to build a Hexastix. In 72 easy steps. https://www.youtube.com/watch?v=DelH1S32dOg

If you need 85 custom pencils in your life (The 67 you need, plus we've put in a few spares) you can buy a set while stocks last over on Maths Gear. Sorry the set is quite expensive. This is just the cost price I originally paid to get them made. Elastic bands are not included. https://mathsgear.co.uk/products/prism-pencils-pack-of-85

Huge thanks to my Patreon supporters. They are as special as a triangular pencil. https://www.patreon.com/standupmaths

CORRECTIONS - None yet, let me know if you spot anything!

Filming and editing by Alex Genn-Bash Written and performed by Matt Parker Produced by Nicole Jacobus Music by Howard Carter Design by Simon Wright and Adam Robinson

MATT PARKER: Stand-up Mathematician Website: http://standupmaths.com/ Love Triangle: https://mathsgear.co.uk/products/love-triangle-by-matt- parker-signed