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，左氏错觉行线看起来不行。

Parallel lines are lines that never join.

行线是永不相交的线。

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, 行线是在同一上永不相交的线。

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

目前常用的量算法有格纸法、行线法、求仪法。