Why A4 Paper is 210 x 297mm (The Math Secret)

Ajouté : 2026-05-16

[00:00:00]Grab a sheet of A4 printer paper. You are holding a tiny [music] infinite loop. Its size is 210 by 297 mm, [music] which sounds like someone measured it during a fire. They did not. Those cursed numbers are engineered, so when you cut A4 in half, both halves keep the exact same shape. Cut again, same shape.

[00:00:22]That only works with a 1 to root 2 rectangle, which is why photocopiers can shrink pages, printers can make booklets, and posters can scale up without wrecking the layout. A4 is not boring. It is the printer's secret handshake.