这是平行四边形的对边.These are the opposite sides of the parallelogram.这种作图法常被称为矢量相加的平行四边形法则.This construction is often called the parallelogram law of addition of vectors.梯形是具有两平行边的四边形.A trapezoid is a quadrilateral with two para...

“四边形”的英语可以翻译为：quadrilateral，tetragonum，quadrangle ...

“四边形”的拼音为：sì biān xíng...