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Number & MeasureGreekEnglish

Perimeter

/pəˈrɪmɪtər/noun

The continuous boundary of a shape or area, or its total length.

The Greek roots

περί
perí
around
+
μέτρον
métron
measure

Literally: measure around

The story of the word

περίμετρος did duty for the circumference of a circle and the boundary of a polygon alike, since both are the measure taken around. English borrowed it as a geometrical term in the early fifteenth century and left it there for five hundred years. The military and security sense, a perimeter to be held or breached, is twentieth century, and the two meanings now rarely meet in the same sentence.

How it travelled
Ancient Greek → Latin → English
First recorded
15th century

The same roots elsewhere

Other languages reached for exactly the same Greek pieces.

Same family

diametergeometrymetricisometric

In a sentence

Add the four sides and you have the perimeter; that is the whole trick.

Built on the same root

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