supplementary

/ˌsʌplɪˈmentri/ (bre, ipa) · /ˌsʌplɪˈmentri/ (ame, ipa) · /ˌsə-plə-ˈmen-tə-rē -ˈmen-trē/ (ame, mw)

supplementary — adjective

  • supplementarypositive
  • more supplementarycomparative
  • most supplementarysuperlative

1. describing two angles that, when added together, total exactly 180 degrees and t

1.形容詞B2
釋義

describing two angles that, when added together, total exactly 180 degrees and therefore form a straight line when placed side by side.

例句

If one angle measures 75 degrees, then its supplementary angle must be 105 degrees.

supplementary angle + measure [number] degrees

Quan found the supplementary angle for a 65-degree angle on the geometry worksheet.

反義詞
  • complementary

    refers to angles totalling 90 degrees instead of 180

文法句型

supplementary + angle

supplementary to + noun phrase

用法筆記

In geometry, supplementary is often paired with complementary (angles totalling 90 degrees). A common exam task is to calculate a supplementary angle given one part of the pair.

常見錯誤

❌Complementary angles add up to 180 degrees.
✅Supplementary angles add up to 180 degrees.
💡Complementary angles total 90 degrees; supplementary angles total 180 degrees.

2. offered or used as an addition to what already exists, so that the original thin

2.形容詞B2
釋義

offered or used as an addition to what already exists, so that the original thing becomes better, more complete, or better supported.

例句

Christopher took a supplementary course in data analysis to strengthen his job skills.

supplementary course [in subject]

The doctor recommended a supplementary vitamin D tablet during the dark winter months.

supplementary vitamin / supplement

同義詞
  • additional

    more neutral and widely used; lacks the nuance of 'filling a gap'

  • extra

    more informal; common in everyday speech

  • supplemental

    more common in American English; identical in meaning

  • auxiliary

    suggests a supporting or backup role, often for equipment or staff

反義詞
  • main

    the primary source or item, rather than something added to it

  • primary

    the first or most important, not additional

文法句型

supplementary + noun

用法筆記

Almost always used before a noun — you would not say 'this information is supplementary' without following it with 'to' (e.g., 'supplementary to the main report'). In everyday speech, additional or extra are more common than supplementary.

常見錯誤

❌We need a complementary report for the project.' (when meaning extra).
✅We need a supplementary report for the project.
💡Complementary means 'matching or completing each other well'; supplementary means 'added as an extra.'