1.
Amelioration about the Demonstrator of Force Parallelogram Formula;
关于力的平行四边形定则演示仪的改进
2.
A quadrilateral having no parallel sides.
没有平行边的四边形
3.
primitive parallelogram of period
周期的原始平行四边形
4.
a parallelogram with four equal sides; an oblique-angled equilateral parallelogram.
四个边相等的平行四边形；不是直角的等边平行四边形。
5.
A quadrilateral having two parallel sides.
梯形一个有两条平行边的四边形
6.
A trapezoid is a quadrilateral with two parallel sides.
梯形是具有两平行边的四边形。
7.
parallelogram illusion
平行四边形错觉 平行四边形错觉
8.
A four-sided plane figure with opposite sides parallel.
平行四边形一种有四条边且每两条边对应平行的平面图形
9.
a quadrilateral whose opposite sides are both parallel and equal in length.
相对的边平行且长度相等的四边形。
10.
(in US) a quadrilateral with no parallel sides.
（在美国）没有平行边的四边形。
11.
(in US) a quadrilateral with two parallel sides.
（在美国）有两个平行边的四边形。
12.
a parallelogram with four right angles.
有四个直角的平行四边形。
13.
A plane figure with four sides and four angles.
四边形有四个边和四个角的平面图形
14.
double link jib in parallelogram
平行四边形组合臂架
15.
fundamental period parallelogram
原始周期平行四边形
16.
parallel motion linkage
平行四边形悬挂装置
17.
primitive period parallelogram
基本周期平行四边形
18.
a parallelogram with adjacent sides of unequal lengths; an oblique-angled parallelogram with only the opposite sides equal.
相邻的边长度不相等的平行四边形；只有相对的边长度相等的非直角平行四边形。