mặt trụ
Definition
- Noun (Geometry):
- Cylindrical surface: A surface generated by a straight line (the generatrix) moving parallel to itself and always intersecting a fixed plane curve (the directrix). In elementary geometry, it is often described as the curved surface of a right circular cylinder.
- Lateral surface of a cylinder: Specifically refers to the curved face of a cylinder, excluding its circular top and bottom bases.
Usage Examples
- Noun:
- Diện tích của mặt trụ được tính bằng công thức 2πrh. (The area of the cylindrical surface is calculated by the formula 2πrh.)
- Hình học không gian nghiên cứu các hình như mặt trụ và mặt cầu. (Spatial geometry studies shapes such as cylindrical surfaces and spherical surfaces.)
- Anh ấy vẽ một mặt trụ trong bài tập hình học. (He drew a cylindrical surface in the geometry exercise.)
Advanced Usage
- In technical and engineering contexts, "mặt trụ" can describe any cylindrical surface component, such as the exterior of a piston or a roller.
- Bề mặt bên ngoài của trục động cơ là một mặt trụ. (The outer surface of the engine shaft is a cylindrical surface.)
Variants and Related Words
- Hình trụ (n): cylinder (the solid three-dimensional shape, including the bases).
- Một lon nước ngọt có dạng hình trụ. (A soda can has the shape of a cylinder.)
- Trụ tròn (n): circular cylinder (a specific type of cylinder).
- Mặt cong (n): curved surface (a more general term).
Synonyms
- Cylindrical surface: The most direct equivalent in mathematical English.
- Lateral surface: When specifically contrasting with the bases of a cylinder.
Related Terms
- Đường sinh (n): generatrix (the line that generates the surface).
- Đường tròn đáy (n): base circle.
- Trục (n): axis (the central line around which the generatrix moves parallel).