Engineering & MachinesGeometry
The Drill That Makes Square Holes
A rounded triangle can drill an almost square hole
Every drill bit spins, and everything that spins cuts a circle. So how does a real drill leave a hole with four straight sides?
You'll find out
- What rolls smoothly without being round
- How a spinning bit cuts straight sides
- Why some coins have corners
Why it matters
One odd shape links square holes, cornered coins and guitar picks, and shows that round is not the only way to roll.
Play this lesson
Free to play in your browser or on iPhone