What is the name for a shape that is like a capsule, but with two different radii?

Question

I'm looking for the name of a shape that is like a capsule, but where each circle can have different radii. The shape could be described using two circles (two centers and two radii). Something like this (this is a 2D shape, not a lame attempt at 3D):

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score 9 · Accepted Answer · answered Jul 31 '10 at 01:23

9

You can just say it is the convex hull of two circles.

answered Jul 31 '10 at 01:23

Samuel

5,550

Yeah that's a simpler definition. A name would be cool though, as I'd like to use it as the name of a class in a program and ConvexHullOfTwoCircles is not too catchy. – Trillian Jul 31 '10 at 01:29
6

What about Pear? – Qiaochu Yuan Jul 31 '10 at 02:13
1

It looks like a pulley and belt system, so how about PulleyBeltShape? – user115 Jul 31 '10 at 04:45
I'm accepting this because the shape doesn't seem to have a name and this is a helpful definition. – Trillian Jul 31 '10 at 12:56
1

@Qiaochu Haha, Pear's not bad but, if you're into fruits, Avocado seems more fit! – Trillian Jul 31 '10 at 13:05

score 4 · Answer 2 · edited Feb 16 '19 at 22:56

4

Here is an article at Mathworld on Circle-Circle Tangents. Perhaps "CirclesWithTangents"?

_{(source: wolfram.com)}

edited Feb 16 '19 at 22:56

Glorfindel

3,955

answered Jul 31 '10 at 06:27

Dennis Williamson

153

Hmm... not too sure for the name, but thanks for that article, it should be helpful with what I intend to do with this shape. – Trillian Jul 31 '10 at 12:55
@Dennis Williamson Circle with Direct tangents – Narasimham Sep 05 '14 at 23:42

kubashmuba · Answer 3 · 2017-07-19T13:20:23.790

0

I would suggest the name "Capsuloid". I had the same question but in $3D$. One could define the capsuloid ratio as the quotient of smallest radius $r$ to biggest radius $R$. $r\over{R}$ belongs to $[0,1]$, a value of $1$ corresponding to a true capsule.

edited Jul 19 '17 at 13:20

answered Jul 18 '17 at 13:25

kubashmuba

1
1

Please use Mathjax – Arman Malekzadeh Jul 18 '17 at 13:44
Oh great I didn't know it was available! Super noob here :) Thanks! – kubashmuba Jul 19 '17 at 13:21

score 0 · Answer 4 · answered Jul 04 '20 at 15:54

0

I have 3 ideas from which you may be able use to settle upon a suitable name:

a conrod or tapered conrod (as in the big-end small-end connecting rod);
it resembles a pull tab of a zipper; and,
it also resembles the tab pull of a soda can.

answered Jul 04 '20 at 15:54

Pytheorem

69

What is the name for a shape that is like a capsule, but with two different radii?

4 Answers4

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