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# circumference

noun (a circumference, circumferences)

«circumference» in the English dictionary: everyday — its meanings, how the lessons use it, and examples, each with its tree on Mova.

## Everyday

1. (maths) The distance all the way around the edge of a circle; the perimeter of a circle. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#m1)
2. The distance around anything round: the circumference of a tree trunk, of the Earth. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#m2)
3. The edge or boundary of a round area. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#m3)

### In the lessons

In maths lessons the circumference is found with C = pi x d (pi times the diameter) or C = 2 x pi x r, using pi of about 3.14. In science and geography the Earth's circumference is about 40,000 km. Phrases: the circumference of, measure the circumference, find the circumference.

### Examples

- The circumference is the distance around a circle. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#x1)
- A circle with a diameter of 10 cm has a circumference of about 31.4 cm. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#x2)
- Measure the circumference of a tree with a tape measure. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#x3)
- The Earth's circumference is about 40,000 kilometres. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#x4)
- Wrap a string around the tin to find its circumference. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#x5)
- (formal) Calculate the circumference given a radius of 7 cm (about 44 cm). [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#x6)
- Its ring was broad, and from its circumference the rays shot like whirling shafts of fire across the whole sky, flashing in changing radiance from green to red. [tree →](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/#x7)

### Note

Countable; usually "the circumference". Formula: C = pi x diameter = 2 x pi x radius. Traps: do not mix up radius and diameter (diameter = 2 x radius); do not confuse circumference (a length, in cm) with area (in square cm, pi x r x r).

## On Mova

- [Trees and pragmatics of «circumference» in the school dictionary](https://mova.elamur.ai/free/en/corpora/dictionaries/school/C/circumference/): every meaning and example parsed by Mova, with its dependency tree and frames.
- [«circumference» in the school dictionary](https://mova.elamur.ai/free/en/dictionaries/school/w/circumference.html) on Mova free.