complementary angle: meaning, definition, pronunciation and examples
TechnicalFormal/Technical
Quick answer
What does “complementary angle” mean?
One of two angles whose measures add up to 90 degrees (a right angle).
Audio
Pronunciation
Definition
Meaning and Definition
One of two angles whose measures add up to 90 degrees (a right angle).
In a broader sense, refers to one of two elements that together form a complete 90-degree unit, often used conceptually in design, strategy, or analysis to describe two mutually supporting components.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or definitional differences. Spelling of related terms may differ (e.g., 'centre' vs. 'center').
Connotations
Identical technical connotations in both varieties.
Frequency
Equally infrequent in general discourse but standard in mathematical contexts in both regions.
Grammar
How to Use “complementary angle” in a Sentence
Angle A is complementary to angle B.Angles A and B are complementary.The complementary angle of 30° is 60°.Vocabulary
Collocations
Examples
Examples of “complementary angle” in a Sentence
adjective
British English
- The two acute angles in the diagram are complementary.
- We need to identify the complementary angles.
American English
- These two angles form a complementary pair.
- Find the angle complementary to the given one.
Usage
Meaning in Context
Business
Rare. Possibly metaphorical: 'Our skills are complementary, covering a complete skillset.'
Academic
Primary usage. Standard in geometry, trigonometry, and engineering textbooks.
Everyday
Very rare. Limited to homework help or specific DIY/construction tasks.
Technical
Core usage. Precise geometric term.
Vocabulary
Synonyms of “complementary angle”
Neutral
Weak
Vocabulary
Antonyms of “complementary angle”
Watch out
Common Mistakes When Using “complementary angle”
- Using 'complimentary' (meaning free or flattering).
- Confusing with 'supplementary angles' (sum to 180°).
- Saying 'complementary angle' for a single angle without reference to its pair.
FAQ
Frequently Asked Questions
Complementary angles sum to 90 degrees (a right angle), while supplementary angles sum to 180 degrees (a straight angle).
No, by definition, if two angles are complementary, each must be less than 90 degrees (acute). Their sum is exactly 90.
No, they do not. Complementary is a relationship based solely on the sum of their measures. They can be anywhere in a figure.
Subtract the given angle's measure from 90 degrees. For example, the complement of 30° is 90° - 30° = 60°.
One of two angles whose measures add up to 90 degrees (a right angle).
Complementary angle is usually formal/technical in register.
Complementary angle: in British English it is pronounced /ˌkɒmplɪˈmɛnt(ə)ri ˈæŋɡ(ə)l/, and in American English it is pronounced /ˌkɑːmplɪˈmɛn(t)əri ˈæŋɡəl/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think 'C' for Complementary and Corner (a right angle is a perfect corner). Both start with C and combine to 90°.
Conceptual Metaphor
PERFECT PAIRING (Two distinct parts that together create an ideal, complete whole, like partners in a dance).
Practice
Quiz
Which of the following statements about complementary angles is TRUE?