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Euclid's first theorem

theorem in Euclidean geometry
Intangible theorem Q3921905

Facts

6 properties
Instance of
theorem
Part of
Pythagoras–Euclid theorems[4]
Defining formula
\overline{AC} : \overline{CB} = \overline{CB} : \overline{CH}, \overline{CB}^{2} = \overline{AC} \cdot \overline{CH}[5][6]
Discoverer or inventor
Euclid[2]
Maintained by WikiProject
WikiProject Mathematics[7]
Named after
Euclid[3]
🏷️ Also known as
en Cathetus theorem en Euclid's first theorem en Euclid's proof of the Pythagorean theorem de Euklidischer Kathetensatz de Kathetensatz de Kathetensatz des Euklid fr premier théorème d'Euclide it primo teorema di Euclide it teorema del cateto di Euclide uk Перша теорема Евкліда zh 射影定理
🔖 Identifiers · 2
Image (Wikimedia Commons)
Kathetensatz.svg ↗
Google Knowledge Graph ID
/g/122cc1_m, /g/121hg7f4

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🔗 Connections
Discoverer or inventor 1
Euclid
Instance of 1
theorem
Maintained by WikiProject 1
WikiProject Mathematics
Named after 1
Euclid
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Summary

Euclid's first theorem is a theorem[1].

Related Entities

Euclid

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [2] ↑ . wikidata.org.
  2. [3] ↑ . wikidata.org.
  3. [4] ↑ . wikidata.org.
  4. [5] ↑ . wikidata.org.
  5. [6] ↑ . wikidata.org.
  6. [7] ↑ . wikidata.org.

Class ancestry

  1. [1] ↑ . Wikidata. wikidata.org.

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APA 4ort.xyz Knowledge Graph. (2026). Euclid's first theorem. Retrieved November 4, 2026, from https://4ort.xyz/entity/euclid-s-first-theorem
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BibTeX @misc{4ortxyz_euclid-s-first-theorem_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{Euclid's first theorem}}, year = {2026}, url = {https://4ort.xyz/entity/euclid-s-first-theorem}, note = {Accessed: 2026-11-04}}
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