It’s been known since 1882 that it’s impossible to construct a square with the area of a given circle using only a compass and straightedge.
But in 1977 Thomas Elsner showed that the task becomes possible if the circle is allowed to roll:
It’s been known since 1882 that it’s impossible to construct a square with the area of a given circle using only a compass and straightedge.
But in 1977 Thomas Elsner showed that the task becomes possible if the circle is allowed to roll: