For two given unequal straight lines, to cut off from the greater a straight line equal to the lesser. * Let $AB$ and $C$ be the two given unequal straight lines, of which let the greater be $AB$. * So it is required to cut off a straight line equal to the lesser $C$ from the greater $AB$.
Given two arbitrary segments in the plane, which are not congruent, it is possible to cut the segment with bigger length such that one of its two subsegments is congruent to the smaller segment.
Proofs: 1
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Sections: 30