Pentagonal bipyramid is currently a Mathematics and mathematicians good article nominee. Nominated by Dedhert.Jr (talk) at 04:53, 20 December 2025 (UTC) Any editor who has not nominated or contributed significantly to this article may review it according to the good article criteria to decide whether or not to list it as a good article. To start the review process, click start review and then save the page. See the good article instructions. Short description: Two pentagonal pyramids joined at the bases

This article is rated B-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Mathematics Low‑priority This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics Low This article has been rated as Low-priority on the project's priority scale. Polyhedra This article is within the scope of WikiProject Polyhedra, a collaborative effort to improve the coverage of polygons, polyhedra, and other polytopes on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PolyhedraWikipedia:WikiProject PolyhedraTemplate:WikiProject PolyhedraPolyhedra ??? This article has not yet received a rating on the project's importance scale.

In the case of a pentagonal bipyramid, it has one type of closed geodesic crossing one edge of triangular faces

Er what? How can a closed geodesic cross only one side of a face? —Tamfang (talk) 02:18, 18 March 2025 (UTC)[reply]

@Tamfang Ah sorry for this. I was trying to explain how can a closed geodesic cross triangular faces on the apical and equatorial edges. It's somehow difficult to present a better explanation, and you can see on the page 135 [1] and page 136 for the illustration. Dedhert.Jr (talk) 04:03, 18 March 2025 (UTC)[reply]

having seen the picture – I will have to give some thought to expressing it. —Tamfang (talk) 04:20, 18 March 2025 (UTC)[reply]

@Tamfang Thank you. I'll leave this to you. Dedhert.Jr (talk) 04:40, 18 March 2025 (UTC)[reply]