# ummál

Definition from Wiktionary, the free dictionary

## Icelandic[edit]

### Etymology[edit]

From Old Norse *ummál*. See the Old Norse *ummæli* (Icelandic *ummæli*). Compare the Icelandic *um* (“around”) + *mál* (“measurement”) and *mæla* (“measure”).

### Noun[edit]

**ummál** n (*genitive singular* **ummáls**, *nominative plural* ** ummál**)

- (mathematics) a perimeter; (sum of the distance of all the lengths of the sides of an object)
- (mathematics) a circumference; (length of a line that bounds a circle or other two-dimensional figure)

#### Derived terms[edit]

- brjóstummál
- meðalbrjóstummál
- jafn að ummáli (isoperimetric)
- ummálsjafn (isoperimetric)
- ummálsjafnaðarójafna (isoperimetric inequality)
- ummálsjafnaðarverkefni (isoperimetric problem)
- ummálsmikill
- ummálsregla (half-angle formula)