**Online Math Classes > Math Concepts > Geometry > Geometric Shapes – 2D and 3D Shapes**

Every materialistic object we use has some shape. For example, a sheet of paper, a TV remote, a book, a box and so on has got some shape. Geometric shapes has been categorized into two types: Planar shapes and Solid shapes.

A shape that is flat in appearance and has only two dimensions (length and width) is known as planar shape. Example: Square, Triangle

A shape that is not flat in shape and has three dimensions (length, width and height) is known as solid shape. Example: Cube, Cuboid

## 2D Shapes

Classification of 2 dimensional shapes can be represented using the following flow chart.

## Examples of 2D shapes

### Polygons

A 2D shape that is formed by straight lines is called a polygon. A polygon that has all sides and angles equal is called a regular polygon. A polygon that has all its sides and angles unequal is called irregular polygon.

Polygons geometric shapes are classified based on the number of sides and the angles between the sides.

Let us acquire knowledge of types of polygons and their properties.

#### Triangle

A polygon which has three sides is called a triangle. Different types of triangles include:

#### Quadrilaterals

A polygon which has four sides is called a quadrilateral. Different types of quadrilaterals include:

## 3D Shapes

Geometric Shapes are said to be 3D if they are measured in three directions-length, width, and height. All objects that we see around us are 3D shapes. For example, a photo frame, a coffee mug, a cake, a pencil and so on.

3D shapes in mathematics are referred to as solids. Solids have faces, edges, and vertices. Faces are the flat shape seen on any one side view of an object. Edges are the intersecting line segments of two faces. Vertex is a point of intersection of three edges.

3D shapes which are composed of flat polygon faces, straight edges, and pointed vertices are called polyhedrons. Shapes which have curved surfaces are non-polyhedrons. For example: sphere, cone, cylinder.

A polyhedron that has identical regular polygonal faces is called platonic solids. There are only five platonic solids.

Some of the 3D shapes are listed below.

## Geometric Shapes in Real-Life

In our day-to-day life, there are numerous objects that resemble any of 3 D shapes. Let us see some of the objects and their geometrical shapes.

Try yourself!

Look around your surroundings and note down the 3D shapes which you can identify.

### Scutoid

The scutoid is a three-dimensional irregular eight-faced structure that is best described as a seven-faced pentagonal prism. Scutoids are found in the curvy parts of human organs, where epithelial cells adopt the form to fit in, stay stable, and conserve energy.

### Paper

Even though paper is thick, most people believe it is flat. Although the thickness is modest and barely noticeable, it is present. The dimensions of the paper are length, breadth, and depth. Paper is shaped like a cuboid. That is the rectangle’s 3D equivalent.

Know more about other concepts of Geometry on Heron’s Formula , Area of Triangle, Area of Circle, What is Perimeter and What is Triangle.