Geometry

Three-dimensional shapes

3-D (three-dimensional) shapes are solid shapes or objects that have three dimensions - length, depth and width. These are shapes that occupy space. This means that we can touch and feel them. 3-D shapes have thickness or depth. The attributes of a three-dimensional figure are faces, edges and vertices.

Here we will discuss these three-dimensional shapes –

(i) cube     (ii) cuboid     (iii) sphere     (iv) cone     (v) cylinder

Cube:

A Cube is a solid three-dimensional figure, that has each face square-shaped. Rubic cubes, dice, ice cubes, etc. are examples of cubes that are easily seen in our surroundings.

A cube has 6 square-shaped plane faces, 8 vertices and 12 edges.

Cuboid:

A cuboid is a solid three-dimensional shape having each face rectangular shaped. Bricks, diaries, lunch boxes, etc. are examples of cuboids from our surroundings.

A cuboid has 6 rectangular faces, 8 vertices and 12 edges.

Sphere:

A sphere is a three-dimensional solid figure, which is round in shape. The sphere doesn’t have any edges and corners. Football, globe, orange are examples of spheres from our surroundings.

A sphere has a curved surface and doesn’t have any vertex and plane face.

Cone:

A cone is a three-dimensional geometric figure that has a flat surface and a curved surface pointed towards the top. The pointed end of the cone is called the apex, whereas the flat surface is called the base. Traffic cones, birthday caps, ice cream cones etc are examples of cones from our surroundings.

A cone has a vertex, one plane surface and one curved surface.

Cylinder:

A cylinder is a three-dimensional solid figure that has two identical circular faces. These circular faces are joined by a curved surface. Pencil holders, water tanks, canned food are examples of the cylinder from our surroundings.

A cylinder has two flat faces and one curved face. There are no corner in a cylinder.

Origami

Here we will make a boat by using a folding technique.