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a parallelogram: a four-sided geometric figure in which both pairs of opposite sides are parallel
The standard math-class term for a parallelogram. A quadrilateral in which each pair of opposite sides is parallel and equal in length, and opposite angles are equal. Rectangles, rhombi (diamonds), and squares are all special cases. Taught in Japanese elementary school (小学校) around fourth or fifth grade as part of basic geometry.
平行四辺形の面積を求める。
To find the area of a parallelogram.
この四角形は平行四辺形だ。
This quadrilateral is a parallelogram.
平行四辺形では向かい合う辺の長さが等しい。
In a parallelogram, opposite sides are equal in length.
平行四辺形の面積は、底辺×高さで求めることができる。
The area of a parallelogram can be found by multiplying the base by the height.
Composed of 平行 (parallel) + 四辺形 (quadrilateral, four-sided figure). Literally "parallel quadrilateral." The standard term used throughout Japanese elementary, middle, and high school mathematics.
KEY PROPERTIES (the way they are stated in Japanese math classes):
- 向かい合う辺は平行で長さが等しい: opposite sides are parallel and equal in length
- 向かい合う角の大きさは等しい: opposite angles are equal
- 対角線はそれぞれの中点で交わる: the diagonals bisect each other
- 面積 = 底辺 × 高さ: area = base × height
COMMON COLLOCATIONS:
- 平行四辺形の面積: the area of a parallelogram
- 平行四辺形の性質: properties of a parallelogram
- 平行四辺形を描く: to draw a parallelogram
- 平行四辺形になる条件: the conditions for (a shape) to be a parallelogram
RELATED GEOMETRY TERMS:
- 長方形: rectangle — a parallelogram with all right angles
- 正方形: square — a rectangle with all sides equal
- ひし形: rhombus, diamond — a parallelogram with all sides equal
- 台形: trapezoid / trapezium — a quadrilateral with only one pair of parallel sides
- 四角形: quadrilateral — the general term for any four-sided figure
- 多角形: polygon
- 平行: parallel
- 対角線: diagonal (line)
- 底辺: base (of a triangle or parallelogram)
- 高さ: height
REGISTER:
Neutral and technical. A standard math-class word; used mostly in educational, mathematical, and technical-drawing contexts.