كرة

Also known as 2-sphere, orb

شكل هندسي

AI overview

A sphere is a perfectly round three-dimensional shape where every point on its surface sits at an equal distance from a central point, much like how a circle works in two dimensions. Spheres matter because they are a fundamental geometric form that appears throughout mathematics, nature, and everyday objects like planets and balls, making them essential to understanding spatial relationships and physical properties of the world around us.

AI-generated from the Wikipedia summary — may contain errors.

Key facts

Polyhedron<! Please add only parameters that make sense for a sphere. >.name: Sphere
Polyhedron<! Please add only parameters that make sense for a sphere. >.image: File:Sphere wireframe 10deg 6r.svg
Polyhedron<! Please add only parameters that make sense for a sphere. >.caption: A perspective projection of a sphere
Polyhedron<! Please add only parameters that make sense for a sphere. >.euler: 2
Polyhedron<! Please add only parameters that make sense for a sphere. >.symmetry: Orthogonal group|
Polyhedron<! Please add only parameters that make sense for a sphere. >.type: Smooth surfaceAlgebraic surface

via Wikipedia infobox

Wikidata facts

Subclass of: geometric primitive
Followed by: torus
Follows: circle
Image: Sphere Quadric.png
Said to be same as: Riemann sphere

Show 9 more facts

Commons category: Spheres
Euler characteristic: 2
topic's main category: Category:Spheres
has characteristic: genus
different from: three-ball
Commons gallery: Sphere
on focus list of Wikimedia project: Wikipedia:Vital articles/Level/4
maintained by WikiProject: WikiProject Mathematics
described by source: Encyclopædia Britannica 11th edition

Sources (4)

via Wikidata · CC0

Article · العربية

الكرة أو الفلكة سطح هندسي ثنائي تام التناظر، ينتج عن دوران دائرة حول أحد أقطارها. في الهندسة الإقليدية ثلاثية الأبعاد تعرف الكرة على أنها المحل الهندسي لمجموعة النقاط التي تبعد البعد نفسه وليكن r من نقطة معينة في الفضاء حيث r عدد موجب (ليس بالضرورة صحيحا دائما) ويسمى نصف القطر. تسمى النقطة المعينة بمركز الكرة. كرة الوحدة هي الكرة التي يكون نصف قطرها يساوي 1.

Abstract from DBpedia / Wikipedia · CC BY-SA