• halcyoncmdr@lemmy.world
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    1 day ago

    Someone never had to deal with mathematical proofs, only layman’s definitions.

    All properties of a parallelogram apply:

    • Opposite sides are parallel
    • Opposite sides are congruent
    • Opposite angles are congruent
    • Consecutive angles are supplementary
    • Diagonals bisect each other

    AND

    • All angles are congruent
    • All sides are congruent
    • Diagonals are congruent
    • Diagonals are perpendicular
    • Diagonals bisect opposite angles
    • Eatspancakes84@lemmy.world
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      18 hours ago

      Of course, but such strict definitions only come about because smart people come up with examples like OP when you don’t add the full definition.