三角錐(さんかくすい) さんかくすい noun triangular pyramid; tetrahedron academicscience 1. triangular pyramid; tetrahedron A solid figure with a triangular base and triangular side faces meeting at a single apex. この置物(おきもの)は三角錐(さんかくすい)の形(かたち)だ。🔊 This ornament is shaped like a triangular pyramid. 三角錐(さんかくすい)の体積(たいせき)を求(もと)めなさい。🔊 Find the volume of the triangular pyramid. 折(お)り紙(がみ)できれいな三角錐(さんかくすい)を作(つく)るのは意外(いがい)と難(むずか)しい。🔊 Making a neat triangular pyramid out of origami is surprisingly difficult. Composed of 三角(さんかく) (triangle) + 錐(すい) (a pyramid or cone solid). A basic shape in school geometry.Similar words円錐(えんすい): cone — has a circular base四角錐(しかくすい): square pyramid — has a square base角錐(かくすい): pyramid — the general term for a solid with a polygonal base Related Words Compare: 円錐(えんすい) (cone) Compare: 四角錐(しかくすい) (square pyramid) general Added 2026.6.19 0:20 · Revised 2026.9.2 13:02 29000/29329_sankakusui