周长 (zhōucháng): perimeter

Meanings

Zhège yuán de zhōucháng shì duōshao?

What is the circumference of this circle?

Cāochǎng de zhōucháng dàyuē sì bǎi mǐ.

The track's perimeter is about four hundred meters.

memory

周 = around / a full lap, 长 = length. The 'around-length' — exactly what perimeter means.

周 zhōu

长 cháng