Spheres are round three-dimensional figures. The surface of a sphere is generated when the circumference rotates completely around its diameter. Some of the most important elements of the spheres are the radius, the diameter, the center, the poles, and the chords.

Here, we will learn more details about these elements. Also, we will learn about the geometric figures that are obtained from a sphere. We will use diagrams to illustrate these concepts.

## Fundamental elements of a sphere

The main elements of a sphere are:

- Center
- Radius
- Diameter
- Chord
- Poles
- Parallels
- Meridians
- Equator

### Center

The center is the interior point of a sphere, which is equidistant from any other point on the surface of the sphere.

### Radius

The radius is the distance or line segment from the center to any point on the surface of the sphere.

### Diameter

The diameter is a chord that passes through the center of the sphere. The length of the diameter is equal to twice the length of the radius.

### Chord

The chord is a line segment that joins two points on the surface of the sphere.

### Poles

The poles are the extreme points on the axis that are on the surface of the sphere.

### Parallels

The parallels are the circumferences obtained by cutting the surface of the sphere with planes perpendicular to the axis of rotation.

### Meridians

The meridians are the circumferences obtained by cutting the surface of the sphere with planes that contain the axis of rotation.

### Equator

In geometry, the equator is the circumference obtained by cutting the surface of the sphere in a plane perpendicular to the axis of rotation and passing through the center. The equator divides the sphere into two equal parts.

## Geometric shapes found in a sphere

We can obtain the following geometric figures in a sphere:

- Hemisphere
- Semisphere
- Spherical crescent
- Spherical wedge
- Spherical cap
- Spherical zone

### Hemisphere

A hemisphere is each of the parts of the spherical surface obtained by dividing the sphere with a plane that passes through the center.

### Semisphere

A hemisphere is each of the parts of the sphere obtained by cutting the sphere through the diameter.

### Spherical crescent

A spherical crescent is a part of the spherical surface made up of two planes that intersect at the diameter of the sphere.

### Spherical wedge

A spherical wedge is a part of a sphere that is obtained by cutting the sphere with two planes that meet the diameter of the sphere.

### Spherical cap

A spherical cap is a part of the sphere formed by a secant plane.

### Spherical zone

A spherical zone is a part of the sphere formed by cutting the sphere by two parallel secant planes.

## See also

Interested in learning more about spheres? Take a look at these pages:

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