Geometric Shapes and Solids

In this chapter, we will learn about various shapes that we see in our surroundings. In this article, we will be able to recognise shapes correctly and learn about their characteristics.

Common Geometric Shapes

The common geometric shapes used in our daily lives are shown as:

Geometrical shapes consist of:
One-dimensional shapes (1D)
Two-dimensional shapes (2D)
Three-dimensional shapes (3D)

One Dimensional (1D) Shapes

One-dimensional (1D) shapes have only length. They are simple figures that we can draw using only a line and curves. Examples of one-dimensional shapes are:

Point

Straight line

Ray

Parallel lines

Curves

These 1D shapes are the primary building blocks of geometry and are vital for studying complex shapes in the future.

Two Dimensional (2D) Shapes

These Two-dimensional (2D) shapes are plane figures that have two dimensions: length and breadth (or width). 

Characteristics of Two-dimensional shapes:

Sides: The sides of two-dimensional shapes are straight lines. 

Vertices: Vertices are the points where a shape's sides meet. 

Angles: Where two sides of a shape meet, an angle is created.

Examples of 2D shapes are closed figures, shown as:

There are certain prefixes that aid in understanding the figure's shape, such as:

Tri – 3

Quad – 4

Penta – 5

Hexa – 6

Hepta – 7

Octa – 8 and many more……

Let’s discuss more about the plane figure.

Triangle: A closed shape that has three straight lines.

Quadrilateral: It is a closed shape with four straight lines. Examples: rectangle, square, parallelogram, kite, rhombus and trapezium.

Pentagon: A closed shape that has five straight lines.

Hexagon: A closed shape that has six straight lines.

Heptagon: A closed shape that has seven straight lines.

Octagon: A closed shape that has eight straight lines.

Circle: It is a closed shape that looks round with no corners and edges. It is a flat shape that is curved.

Oval: An oval is a shape like an egg and doesn't have any straight lines or corners. It is a flat shape.

These 2D shapes help us understand the basic building blocks of geometry and are important for learning about more 3D shapes.

Example: Name the shape of the playground given below.

a) Circle
b) Oval
c) Hexagon
d) Octagon

Answer: b) Oval

Explanation: The shape of the playground is an oval which is shaped like an egg. It doesn't have any straight lines or corners.

Three-Dimensional (3D) or Solid Shapes

Three-dimensional (3D) shapes are like solid objects that have three special things: length, breadth (or width) and height. 

Some common 3D shapes are the cube, cuboid (like a rectangular box), cone and cylinder.

Example: Which of the following solid shapes does NOT have a quadrilateral?

a)
b)
c)
d)

Answer: d)

Explanation: In options (a), (b) and (c), the objects consist of quadrilaterals (four-sided figures).
In option (d), the object consists of hexagons (six-sided figures).

Example: Identify the shape of the pastry.

a) Cuboid
b) Cube
c) Cylinder
d) Sphere

Answer: a) Cuboid

Explanation: The shape of the pastry is cuboid which has length, breadth and height.