‘Geometry from below’ means geometry as tales about a social practice, in this case about ‘earth-measurement’, to which the Greek word ’geo-metry’ can be directly translated.
The earth is what we live on and what we live on. We divide the earth between us by drawing dividing lines.
If these boundaries disappear, it is important to be able to re-establish them, and this restoration of lines and corners requires that these can be measured.
In ancient Egypt, the Nile thus crossed its banks once a year and brought manure to the fields. After retiring, the divisions had to be re-established.
Geometry from below can be understood as the opposite of geometry from above, deducing geometry from metaphysical truths, axioms.
The following material is not a traditional textbook, but rather an activity guide with suggestions for a range of activities that the reader can perform and report.
So, the idea is that the reader builds his own textbook.