So, take the length unit to be equal to the radius.

也就是说，单位长度等于半径。

youdao

Millimeter is used as length unit in this drawing unless otherwise noted.

除非另有注明，本图采用毫米为长度单位。

youdao

Millimeter is used as length unit in this drawing unless otherwise noted.

除非另有注明，本图采用毫米为长度单位。

youdao