Скачать или смотреть How sure are we? | Introduction to logic and Euclidean geometry | Geometry (TX TEKS) | Khan Academy

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In geometry, science, and in many areas of life, we have vocabulary to describe how sure we are.
Conjecture: A statement that we believe is always true because we have seen many examples of it and no counterexamples.
Postulate: A statement that we believe is always true because people generally agree it is true, but without proof.
Theorem: A statement that we believe is always true because we prove it by a series of other definitions, postulates, and theorems.

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