Meaning & use
acute angle
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Meaning
nouncountablemathematics
An angle that is less than 90 degrees.
Grammar: Countable; use 'an acute angle' or 'acute angles'.
Patterns
- an acute angle of X degrees
- draw an acute angle
- measure an acute angle
The corner of the triangle forms an acute angle of 60 degrees.
In geometry class, we learned to identify an acute angle as any angle smaller than a right angle.
The roof slopes at an acute angle, making the attic feel cozy.
Word forms
| plural | acute angles |
|---|
Common combinations
- at an acute angle
- The two lines meet at an acute angle.
- form an acute angle
- The hands of the clock form an acute angle at 2 o'clock.
- acute angle of X degrees
- An acute angle of 45 degrees is half of a right angle.
- measure an acute angle
- Use a protractor to measure an acute angle accurately.
Synonyms and how they differ
Opposites
Word family
Commonly confused: acute angle or obtuse angle?
acute angle vs obtuse angle
An obtuse angle is greater than 90 degrees but less than 180 degrees, while an acute angle is less than 90 degrees.
Practice
Which of the following angles is an acute angle?
Choose one answer.
An acute angle is less than 90 degrees, so 45 degrees is correct. 90 degrees is a right angle, 120 degrees is obtuse, and 180 degrees is a straight angle.
Make it your own
Write a sentence using “acute angle”, then check it and compare it with the examples above.