[...] let this base-point be indicated by Ax, while the sixth base-point will be indicated by C. Now [c*] contains a threeside formed by a, [...]
Source: wiktionary
Ranked by relevance and common usage.
Keep "threeside" when the sentence already sounds natural, when a synonym would add unintended emphasis, or when readers need the most familiar wording. A synonym should clarify or sharpen the message, not simply make the sentence look more varied.
If two options seem close, choose the one that best matches the audience and purpose of the sentence.
Choose a synonym only if it keeps the core idea of "threeside" intact in the sentence you are editing.
Check whether the replacement sounds more formal, casual, emotional, technical, or forceful than the original word.
Read the full sentence after the swap. Keep the synonym only when the sentence becomes clearer or more precise.
Review note: Synonym lists are ranked with lexical data and reviewed for practical writing value. Use the comparison notes, sentence evidence, and source labels together; a high-ranking synonym can still be wrong when the audience, register, or grammar changes.
After choosing a replacement for "threeside", read the sentence once for meaning and once for rhythm. The best synonym should feel natural in the full sentence, not only accurate in a word list.
If the synonym makes the sentence slower, vaguer, or more dramatic than intended, keep "threeside" or choose a simpler alternative from the closest-match group.
4 total sentences available.
[...] let this base-point be indicated by Ax, while the sixth base-point will be indicated by C. Now [c*] contains a threeside formed by a, [...]
Source: wiktionary
Pappus tells us that Menelaus in his Sphaertca calls the figure in question (the spherical triangle) a 'threeside' [...]
Source: wiktionary
A triangle is then defined as the figure formed by the aggregate of all the segments joining the respective vertices of a three-side to points on the opposite sides.
Source: wiktionary
If a straight line passes through a point of one of the sides of a threeside it must contain at least one point of one of the other sides...For the fourside we define the area to be the sum of the areas of the four threesides in which it is divided by its diagonals.
Source: wiktionary
Closest matches include triangular.
Compare the replacement against real sentence context. This entry includes sample sentences so you can check tone, grammar, and meaning before swapping words.