Page 171 - Maths Skill - 3

Shapes Formation 169

The shapes, we learned in the previous class that if you draw a shape that looks flat, like
a circle, square, or triangle, those are 2-D (two-dimensional) shapes. Let us learn about

3-D (three-dimensional) Shapes: cube, cuboid, cylinder, cone, and sphere. They have
three dimensions: length, width, and height. You can hold them, stack them, and even
fill them up with things like toys because they have space inside. Each shape is unique
and special in its own way.
The descriptions of 3-D shapes are as follows.
Vertex
(i) Cube

A cube is like a box. It has six faces that are all square.
Each face of a cube is the same size, and all edges are Edge
of the same length. It has 8 vertices and 12 edges.
Face
(ii) Cuboid
Face
Vertex Cuboids are also like boxes, but they can be longer
or shorter. They have six faces, just like cubes, but

Edge their faces are not all squares. They look like as
rectangle. It has 12 edges and 8 vertices.

(iii) Cylinder Flat circular face

A cylinder is like a can of soda or a rolling Curved face
pin. A cylinder has three faces. It has two flat
circular faces and one curved face. Flat circular face Curved edge

Vertex
(iv) Cone
Curved face A cone has two faces. It has a circular face at the bottom

Curved edge
(flat face) and one curved. It has one vertex and 1 curved
Flat circular face edge.

(v) Sphere

A sphere is like a ball. It’s completely round, just like Earth! Spheres
have no edges or vertex. A sphere has one curved face.

Properties of 3-D Shapes

3-D shapes have some properties with respect to their faces, vertices and edges.

� Vertices: The points where edges meet in a 3D shape.

� Faces: The flat surfaces that make up a 3D shape.

� Edges: The line segments that connect two vertices in a 3D shape.