The perpendicular distance from the base of a geometric figure to the opposite vertex, parallel side, or parallel surface.

平行面（底面）且侧面都是平行四边形的多面体。

youdao

If the glass were kept hot enough, it would flow over the molten tin until the top surface was also flat, horizontal and perfectly parallel to the bottom surface.

如果玻璃保持足够的温度，它就会在熔化的锡中流动，直到顶部表面也变得平整、水平，与底部表面完全平行。

youdao

If the universe's space-time is positively curved, like the surface of a sphere, parallel beams would come together.

如果宇宙的时空像球体表面一样正向弯曲，平行的光线就会交合在一起。

youdao

However, as its name suggests, it runs parallel to the surface of the material that is propagating it, rather than penetrating this material.

ECONOMIST: Solar energy

Mindful that a narrative so complex could never work as a movie, Snyder has jettisoned several parallel subplots, which will surface as DVD extras and in director's cuts.

CNN: 'Watchmen' finally ticks toward big-screen release

Pricing 150, 000 equity options in a second or assessing how much crude oil sits in a pocket 6 miles below the earth's surface are massively parallel mathematical computing problems for which graphics processors are peculiarly equipped.

FORBES: Magazine Article