Radius
masculine
The German word for radius is Radius. Wiktionary also lists Halbmesser.
Meaning: length of this line segment (noun)
Ways to say it
| German | Note |
|---|---|
| Radius | masculine |
| Halbmesser | masculine, rare |
The term refers to the length of this line segment (noun).
Which one should you use?
While Radius is the standard term, the word Halbmesser can also be used, though it is rare.
How does it change in a sentence?
The plural of Radius is Radii. When using the genitive case (meaning 'of the radius'), the noun follows a strong declension pattern and changes its ending to -s, appearing as des Radius.
Did you know?
- The word Halbmesser literally translates to 'half-knife'. It describes the radius as half of the 'diameter', which in German is Durchmesser or 'through-knife'.
- The German term Radius is borrowed directly from the Latin radius, which originally referred to the spoke of a wheel.
- In German, the plural Radii is used in technical contexts, but the plural Radiusse is also acceptable in general speech, despite the Latin origin.
Examples in context
- Die Fläche eines Kreises ist eine Funktion des Radius.The area of a circle is a function of its radius.This sentence illustrates how the area of a circle relates to the Radius.Tatoeba #13423492 by Waldelfe, translation #13391971 by frpzzd
- Wie berechnet man den Radius, wenn man den Umfang kennt?How is the radius calculated, when the circumference is known?This sentence shows how to ask about calculating the Radius using the circumference.Tatoeba #4007730 by Zaghawa, translation #4021618 by hellosunshine
- Die Fläche eines Kreises kann als Funktion des Radius ausgedrückt werden.The area of a circle can be expressed as a function of its radius.This sentence explains that the area of a circle can be expressed as a function of the Radius.Tatoeba #13422223 by Waldelfe, translation #13391972 by frpzzd
- Der Radius dieses Kreises beträgt 5 Zentimeter.The radius of this circle is 5 centimeters.
- Schau mal, wie groß der Halbmesser dieses Kreises ist!Look at how big this circle's radius is!
- 2 more sentences on Tatoeba
Example conversation
A student and a teacher are looking at a geometry textbook.
- MaximilianWie lang ist dieser Radius?How long is this radius?
- LauraDer Radius beträgt fünf Zentimeter.The radius is five centimeters.
- MaximilianKann ich den Radius selbst messen?Can I measure the radius myself?
- LauraJa, nimm einfach ein Lineal.Yes, just use a ruler.
Sources
- Wiktionary, “radius” translations and entries Radius, CC BY-SA 4.0, dump of 2026-09-26.
- Word origins: Wiktionary entries Radius, CC BY-SA 4.0.
- Example sentences: Tatoeba CC BY 2.0 FR.
