Author Shelley Pearsall visited Copley Middle School in Ohio earlier this month. One of her books, All Shook Up, is about a high school that built the world's largest tetrahedron -over 8 feet tall!
To prepare for her visit, the fifth- and sixth-grade students built a "Rainbow Tetrahedron," which is a giant three-dimensional pyramid made of thousands of smaller folded paper pyramids.
"There are 21,000 individual pyramids in the structure," said librarian Bonnie Hershey. "The students folded and glued them and then we had parents come in to help build it up."
The resulting structure is 16 feet tall, which Pearsall said was the largest tetrahedron she's seen in all the schools she has visited. Link -via reddit
(Image credit: Megan Rozsa)