write the faces, vertices, edges of cube, cuboid triangular prism ,triangular pyramid, pentagonal pyramid and hexagonal prism
Answers
Answer:
6 faces, 12 edges, 8 vertices in a cube.
Same for cuboid.
5 faces, 9 edges, 6 vertices in a ∆ prism.
4 faces, 6 edges, 4 vertices in a ∆ pyramid.
6 faces, 10 edges, 6 vertices in a pent. pyra.
8 faces, 18 edges, 12 vertices in a hex. prism.
Answer:
Faces, Vertices and Edges of a 3-dimensional Figure:
(i) Faces: Each flat part of a solid is called its face.
(ii) Vertices: Each corner where three faces of a solid meet is called its vertex. The plural of vertex is vertices.
(iii) Edges: The two faces of a solid meet in a line, called an edge.
Now, we shall discuss about the faces, vertices and edges of some 3-dimensional figures having flat faces.
I. Cuboid:
A solid bounded by six rectangular plane faces is called a cuboid.
A box, a matchbox, a book, a brick, a tile, etc., are all in the shape of a cuboid.
In the adjoining figure, ABCDEFGH is a cuboid.
(i) Faces of a Cuboid:
A cuboid has 6 faces.
In the given figure, the 6 faces of the cuboid are:
ABCD, EFGH, ADHE, BCGF, ABFE and DCGH.
(ii) Vertices of a Cuboid:
A cuboid has 8 vertices.
In the given figure, the 8 vertices of the cuboid are:
A, B, C, D, E, F, G, H.
(iii) Edges of a Cuboid:
A cuboid has 12 edges.
In the given figure, the 12 edges of the cuboid are:
AB, BC, CD, DA, EF, FG, GH, HE, AE, DH, BF, CG.
II. Cube:
A cuboid whose length, breadth and height are equal is called a cube.
Dice, sugar cubes, ice cubes, etc., are all examples of a cube.
In the adjoining figure, ABCDEFGH is a cube.
(i) Faces of a Cube:
A cube has 6 faces.
In the given figure, the 6 faces of the cube are:
ABCD, EFGH, ADHE, BCGF, ABFE and DCGH.
(ii) Vertices of a Cube:
A cube has 8 vertices.
In the given figure, the 8 vertices of the cube are:
A, B, C, D, E, F, G, H.
(iii) Edges of a Cube:
A cube has 12 edges.
In the given figure, the 12 edges of the cube are:
AB, BC, CD, DA, EF, FG, GH, HE, AE, DH, BF, CG.
Note:
Here, in three-dimensional figures we will discuss about right prism arid regular pyramid.