1. A square is a type of quadrilateral with four equal sides.
正方形是一种四边等长的四边形。

2. The teacher asked students to draw a quadrilateral on the board.
老师让学生在黑板上画一个四边形。

3. In geometry, a quadrilateral can have different shapes and angles.
在几何学中，四边形可以有不同的形状和角度。

4. A rectangle is a special kind of quadrilateral.
长方形是一种特殊的四边形。

A: What is a quadrilateral?
A：什么是四边形？

B: It is a shape with four sides and four angles.
B：它是一个有四条边和四个角的图形。

1) 具有四条边的平面几何图形

2) 包括正方形、矩形、梯形等

3) 可分为凸四边形与凹四边形

4) 常见于基础几何学习

1. 四边形；有四条边和四个角的平面图形。

e.g. A rectangle is a quadrilateral with right angles.
矩形是一种具有直角的四边形。

noun

1. A polygon with four edges (sides) and four vertices (corners).

Synonym: quadrangle, tetragon