Why 4d geometry makes me sad

A series of delightful geometry puzzlesBonus video with extra puzzles: The artwork at the end is by Kurt Bruns Thanks to Daniel Kim for sharing the first two puzzles with me. He mentioned the earliest reference he knows for the tile puzzles is David and Tomei’s AMM article titled “The problem of Calissons.“ The idea to include the tetrahedron volume example was based on a conversation with Po Shen Lo about these puzzles, during which he mentioned the case of one dimension lower. I received the cone correction to the proof of Monge’s theorem from Akos Zahorsky via email. Also, the Bulgarian team leader Velian Velikov brought up the same argument to me and mentioned “ I came across it in a book I found online titled ’Mathematical Puzzles’ by Peter Win ... #3Blue1Brown #Mathematics #three_blue_one_brown #3_blue_1_brown #3b1b #3brown1blue #3_brown_1_blue #three_brown_one_blue 20241108 piJkuavhV50