(ていめん)

ていめん
noun
bottom surface; base; underside
1. bottom surface; base; underside
The lowest surface of an object, container, or geometric shape. Used both in everyday contexts (the bottom of a box) and in mathematics (the base of a solid figure).
(はこ)底面(ていめん)名前(なまえ)()く。
To write one's name on the bottom of the box.
底面(ていめん)面積(めんせき)(もと)めなさい。
Calculate the area of the base.
この円柱(えんちゅう)底面(ていめん)半径(はんけい)()センチの(えん)である。
The base of this cylinder is a circle with a radius of five centimeters.

Composed of (てい) (bottom) and (めん) (surface, face). Used in both everyday and mathematical/technical contexts.

COMMON COLLOCATIONS:

  • 底面(ていめん)面積(めんせき): area of the base
  • 底面(ていめん)(せき): base area
  • 底面(ていめん)(たい)ら: the bottom is flat
  • 底面(ていめん)()()め: non-slip on the bottom

SIMILAR WORDS:

  • (そこ): bottom — more casual and general; the bottom of a bag, ocean, etc.
  • 裏面(りめん): reverse side / back — the opposite side of a flat object, not necessarily the bottom
  • 下面(かめん): lower surface — the underside, similar but less common

NOTE:
In mathematics, 底面(ていめん) specifically refers to the base of a three-dimensional figure such as a prism, cylinder, or pyramid. This is a common term in Japanese math education.