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:
The center is the interior point of a sphere, which is equidistant from any other point on the surface of the sphere.
The radius is the distance or line segment from the center to any point on the surface of the sphere.
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.
The chord is a line segment that joins two points on the surface of the sphere.
The poles are the extreme points on the axis that are on the surface of the sphere.
The parallels are the circumferences obtained by cutting the surface of the sphere with planes perpendicular to the axis of rotation.
The meridians are the circumferences obtained by cutting the surface of the sphere with planes that contain the axis of rotation.
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:
- Spherical crescent
- Spherical wedge
- Spherical cap
- Spherical zone
A hemisphere is each of the parts of the spherical surface obtained by dividing the sphere with a plane that passes through the center.
A hemisphere is each of the parts of the sphere obtained by cutting the sphere through the diameter.
A spherical crescent is a part of the spherical surface made up of two planes that intersect at the diameter of the sphere.
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.
A spherical cap is a part of the sphere formed by a secant plane.
A spherical zone is a part of the sphere formed by cutting the sphere by two parallel secant planes.
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