Vernacular Question

[jmartt]

I'm sure that anyone reading this will know of what I'm about to describe. My question is if there's a common term for it that I've not learned.

A curve that is drawn from the end of a line, whose radial line, drawn to the beginning of the curve, at the point of curvature, makes a 90 degree angle with the line is called a(n) "X" curve.

Is there a correct term for "X"? A cursory search of Google and textbooks I have on hand didn't fill it in. I've always referred to these curves as "tangent curves". But a bright young man in academia recently informed me that this was oxymoronic, and I can appreciate his take on that. Is there a better adjective to use for "X" than "tangent"?

[Anonymous]

Since a generalized curve is defined as “a curved line”
Then it is not necessarily oxymoronic to specifically define one as tangent

[Anonymous]

https://en.wikipedia.org/wiki/Curve

[jmartt]

I don't see this issue addressed on the wiki page, @Anonymous. (I originally didn't see your first post and wondered what you were hoping I'd find, but I see you supplied the link as background to your first post. Thanks.)

Given your moniker, I would think you'd be an authority on the matter. What do you call these curves?

[jmartt]

...Because there must be a way people talk about this. I can't be the only one that has exclaimed something like "Jeez, there's not one tangent curve in this drawing!"

[AllenJessup · Accepted solution]

No. There are Tangent curves and Non-Tangent curves. In order for it to be Oxymoronic. You would have to use tangent to describe non-tangent curves. Even that doesn't fit. Something that might be described as oxymoronic would be "Peacekeeper Missile", Deafening Silence" or "Living Dead". IOW. Word combinations of opposites. Tangent is not the opposite of Curve. Just one flavor.

Also in civil engineering we usually deal with Horizontal Curves and Parabolic Curves. Those can be broken down in to sub-classifications. Sag-Crest, Reverse, Compound, etc.

[Joe-Bouza · Accepted solution]

"Horizontal curves" 

If it isn’t tangent it needs to be revised. No place for non-tangent "horizontal curves" on civil engineering plans.

AKA: HCG... lolol

[jmartt]

Great!

'Nuff said. @AllenJessup @Joe-Bouza . Obviously, other people call em tangent curves as well. I couldn't find the term in a text book, so I wanted to see if this was what other people said. Good. Thanks.

[AllenJessup]

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@Joe-Bouza wrote:

"Horizontal curves" 

If it isn’t tangent it needs to be revised. No place for non-tangent "horizontal curves" on civil engineering plans.

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True. However we sometimes have to deal with non-tangent curves in Surveying. So the distinction has to be made if they're non-tangent.

[Joe-Bouza]

True enough. That is why I distinguished on civil engineering plans.