Assertion: land | /r/HasProperty | flat
Facets:
Source sentences:
text: The simplest coordinate systems assume that the earth is flat and measure from an arbitrary point, known as a 'datum' (singular form of data).
text: Plane surveying assumes the earth is flat.
text: Contrary to popular belief, most people in the Middle Ages did not believe the Earth was flat: this misconception is often called the "Myth of the Flat Earth".