平行线

Zollner's illusion makes parallel lines seem to diverge by placing them on a zigzag-striped background.

将行线置于锯齿形条纹背景上，左氏错觉会让行线看起行。

Parallel lines are lines that never join.

行线是永相交的线。

There are two parallel lines.

这有两条行线。

Parallel lines are, by definition, lines on the same plane that never join.

按定义说, 行线是在同一面上永相交的线。

Graph paper, parallel, and planimeter methods are current tools for acreage calculation.

用的量算面积方法有方格纸法、行线法、求积仪法。