A shooting star crashes onto Earth and a hideous blob emerges. It creeps and leaps, it glides and slides. It’s also unstoppable: no matter what you throw at it, it just re-grows and continues its rampage. The only way to save the planet is to cut the entire blob into precise acute triangles while it sleeps, rendering it inert. Can you stop the blob from destroying the planet?
This TED-Ed math problem is great for the classroom or at home. Get a paper and pencil, and pause this unstoppable blob riddle video at the 2-minute mark to figure out how you can cut the triangle into acute triangles—triangles with angles that are less than 90°—with fewer than 7 cuts with the nano-laser satellite ray.
Need a hint? Think about pizza. Then watch these videos next: Matchstick Triangle Puzzle, The Remarkable Way We Eat Pizza, and The Mathematical Secrets of Pascal’s triangle.
Bonus: Types of Triangles, a Flocabulary math music video.
This Webby award-winning video collection exists to help teachers, librarians, and families spark kid wonder and curiosity. TKSST features smarter, more meaningful content than what's usually served up by YouTube's algorithms, and amplifies the creators who make that content.
Curated, kid-friendly, independently-published. Support this mission by becoming a sustaining member today.