Where this tool comes from
Compass and straightedge
About 2,300 years ago Euclid of Alexandria built geometry in his book the Elements with only two tools: a compass for circles and a straightedge for lines.
One thing to hold: The straightedge has no markings, so you cannot measure with it. You can only draw a line through two points.
Why it matters: Three famous problems (cutting any angle into three equal parts, doubling a cube, squaring a circle) were tried for two thousand years. In the 1800s mathematicians proved that these two tools cannot do them.
What we don’t know: We know almost nothing about Euclid’s own life.
Dates:
- 1837 Wantzel proves that angle trisection and cube doubling cannot be done.
- 1882 Lindemann proves that the circle cannot be squared.