R You go around a circle which has radius r.

你绕圈的半径为。

youdao

r I can take a rod with a radius r, which is 0.5 centimeters.

假设一根棒子半径，等于0。5厘米。

youdao

r I can take a rod with a radius r, which is 0.5 centimeters.

假设一根棒子半径，等于0。5厘米。

youdao