Where does “三角柱” come from?

三角柱 (Japanese) comes from Japanese 三, from Middle Chinese さん.

三角柱 (Japanese): triangular prism

Definitions

  1. triangular prism

Ancestry of “三角柱”, step by step

三角柱 traces back through two separate lines of ancestry.

via Japanese 三

StepLanguageWordMeaning
1Japanese三three, 3; third; three
2Middle Chineseさん—

via Japanese 角柱

StepLanguageWordMeaning
1Japanese角柱prism
Every word from Middle Chinese さん →Every word from Japanese 三 →