regular triangular pyramid; triangular pyramid with equilateral base
A geometric solid: a pyramid whose base is an equilateral triangle and whose other faces are also equilateral triangles (a regular tetrahedron). Used in mathematics and geometry.
Do you remember the formula for finding the volume of a regular triangular pyramid?
This solid is a regular triangular pyramid, and all its faces are equilateral triangles.
三角錐 is a general triangular pyramid (base is a triangle, but not necessarily equilateral). 正三角錐 specifically has an equilateral base and is regular.
正四面体 is a regular tetrahedron, which is the same shape as a regular triangular pyramid. 正三角錐 emphasizes the pyramid aspect, while 正四面体 is the more common term in geometry.
Standard kanji spelling for this geometric term.
Mixed kanji-kana spelling; may be used when 錐 is considered difficult or for readability.
Compound of 正 (regular), 三角 (triangle), and 錐 (pyramid). The term is a straightforward geometric description.