múi cầu
Definition
- Noun (Mathematics):
- Spherical lune: A portion of the surface of a sphere bounded by two great semicircles (half of great circles) that share the same endpoints (antipodal points). It is the spherical analogue of a two-dimensional wedge or a slice of a sphere's surface.
Usage Examples
- Noun:
- Múi cầu được tạo bởi hai nửa đường tròn lớn. (A spherical lune is formed by two great semicircles.)
- Diện tích của một múi cầu phụ thuộc vào góc giữa hai mặt phẳng. (The area of a spherical lune depends on the angle between the two planes.)
Advanced Usage
- In spherical geometry, a múi cầu is fundamental for understanding divisions of a sphere's surface, similar to how a slice divides an orange. The angle between the two defining great circles is called the dihedral angle of the lune.
Variants and Related Words
- Hình cầu (n): sphere.
- Đường tròn lớn (n): great circle.
- Mặt cầu (n): spherical surface.
Synonyms
- Spherical lune (primary).
- Lune (in a spherical context).
Related Concepts
- Spherical wedge: The three-dimensional solid bounded by a múi cầu and the planes defining it, which includes the volume of the sphere.
- Spherical polygon: A múi cầu is the simplest case of a spherical polygon with two sides.