(しかくすい)

しかくすい
noun
square pyramid; rectangular pyramid
1. square pyramid; rectangular pyramid
A pyramid with a quadrilateral base (typically a square or rectangle) and four triangular faces meeting at an apex. A standard solid figure introduced in middle-school geometry, familiar as the shape of the Pyramids of Giza.
四角錐(しかくすい)体積(たいせき)(もと)める。
Find the volume of the square pyramid.
ピラミッドは四角錐(しかくすい)(かたち)をしている。
A pyramid is shaped like a square pyramid.
四角錐(しかくすい)体積(たいせき)は、底面積(ていめんせき)×(たか)さ÷3で(もと)められる。
The volume of a square pyramid is found by multiplying the base area by the height and dividing by three.
数学(すうがく)授業(じゅぎょう)で、四角錐(しかくすい)展開図(てんかいず)をかく練習(れんしゅう)をした。
In math class, we practiced drawing the net of a square pyramid.

Composed of 四角(しかく) (quadrilateral, square) and (すい) (cone, pointed solid). The suffix (すい) is used productively in geometric terms for pyramids and cones.

USAGE:
A technical term in geometry, appearing mainly in math textbooks, lesson materials, and science writing. Like most Japanese geometric-solid names, it is formed with a base-shape name plus (すい).

COMMON COLLOCATIONS:

  • 四角錐(しかくすい)体積(たいせき): volume of a square pyramid
  • 四角錐(しかくすい)表面積(ひょうめんせき): surface area of a square pyramid
  • 四角錐(しかくすい)展開図(てんかいず): net (unfolded diagram) of a square pyramid
  • 正四角錐(せいしかくすい): right square pyramid (with a square base and apex directly above the center)

RELATED GEOMETRIC SOLIDS:

  • 三角錐(さんかくすい): triangular pyramid, tetrahedron
  • 円錐(えんすい): cone (circular base)
  • 角錐(かくすい): pyramid (general term)
  • 四角柱(しかくちゅう): rectangular prism — the prism counterpart to 四角錐(しかくすい)
  • 立方体(りっぽうたい): cube — another common solid figure