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From: "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Newsgroups: sci.math
Subject: Re: The Circles
Date: Tue, 1 Jul 2025 12:23:15 -0700
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On 7/1/2025 4:29 AM, sobriquet wrote:
> Op 01/07/2025 om 07:16 schreef Ross Finlayson:
>> On 06/30/2025 11:29 AM, Chris M. Thomasson wrote:
>>> On 6/28/2025 8:38 PM, Ross Finlayson wrote:
>>>> Oh, been a while, figure I'll post.
>>> [...]
>>>
>>> An ellipse is nothing more than a circle projected in 3d? ;^)
>>>
>>
>> That's frivolous.
>>
>> An ellipse is constructible from a loop of string and two pegs.
>>
>> An image of a circle onto a plane as projected from
>> an incident angle via 3D:  is not an ellipse, either.
>>
>> Ask your shadow.
>>
>>
> 
> Looks like an ellipse to me:
> 
> https://www.desmos.com/3d/syqqdp9cef?translucentSurfaces

:^)

An ellipse, take a parametric circle and use different x and y radii in 
the 2d plane. However, Think of rotating a circle in a 3d projection. It 
visually looks like an ellipse. So, I always found that interesting. If 
I take an ellipse in 2d, it has a rotated circle "counterpart" in 3d? 
Fair enough, kind of? ;^)