Postulates

The basic construction assumptions used throughout Euclid’s Elements (Book I).

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Showing 5 postulates.

← Definitions
  • 1

    To draw a straight line

    To draw a straight line from any point to any point.

  • 2

    To produce a finite straight line

    To produce a finite straight line continuously in a straight line.

  • 3

    To describe a circle

    To describe a circle with any center and distance.

  • 4

    All right angles are equal

    That all right angles are equal to one another.

  • 5

    Parallel postulate

    That, if a straight line falling on two straight lines makes the interior angles on the same side less than two right angles, the two straight lines, if produced indefinitely, meet on that side on which are the angles less than two right angles.

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