face angle
Học thuậtThân thiện
Definition
- Noun:
- The angle formed by two edges of a polyhedral angle: In geometry, a "face angle" is the angle between two adjacent edges that meet at a vertex on a single face of a polyhedron. It is an interior angle of a polygonal face.
Usage
- The term "face angle" is used specifically in the context of solid geometry and polyhedra (three-dimensional shapes with flat faces). It describes an angle on the surface of the shape, not the angle between faces (which is a dihedral angle).
Examples
- Noun:
- To calculate the surface area, you first need to measure each face angle of the pyramid.
- In a regular tetrahedron, all face angles are equal.
- The carpenter checked the face angle of the wooden block to ensure a precise fit.
Advanced Usage
- "Internal face angle": This phrase is sometimes used for clarity to specify it is the interior angle of the polygon forming the face, as opposed to an external angle.
- The sum of the internal face angles in a pentagonal face is 540 degrees.
Variants and Related Words
- Dihedral angle (n): The angle between two intersecting planes or faces of a polyhedron. This is distinct from a face angle.
- The dihedral angle between the side and base of the prism is 90 degrees.
- Polyhedral angle (n): The figure formed by three or more planes meeting at a common point (the vertex). A face angle is a component of a polyhedral angle.
- The polyhedral angle at the apex of the pyramid consists of several face angles.
Synonyms
- Interior angle of a face: A more descriptive synonym.
- Plane angle at a vertex: A technical synonym emphasizing it lies on a flat surface.
Notes
- "Face angle" is a compound noun. The core term being explained is this specific geometric concept. It should not be confused with the separate words "face" or "angle" used independently.
Noun
- the angle formed by two edges of a polyhedral angle