What is the terminology for this geometry ratio?

[doubled]

So if we imagine a rectangle. The aspect ratio is width/height.
What if you want the ratio of the parallel sides? Is there a terminnology for that ratio?

 

[voko]

That ratio is always unity. Why would you need a special word for that?

 

[doubled]

Sorry, my example was a bad one. The actual shape I'm interested in is a trapezoid which I think, theoretically, does not have an aspect ratio defined, but for the purposes of my project I have one defined. If you imagine a trapezoid with the parallel sides oriented vertically, is there a ratio for the parallel sides?

 

[voko]

Unclear: do you want to know whether a special name for this ratio exits, or do you want to find some equation for it?

 

[doubled]

The name.

 

[voko]

I am not aware of any special for that.

 

[Mark44]

Nor am I. The reason there's a name for the ratio of the length to the width of a rectangle is because TV screens, theater screens, and computer monitors are all rectangular, but can have different aspect ratios. There isn't any similar real-world use for trapezoidal image formats, so it's doubtful anyone has come up with a name.