Definition properties formulas and examples of 2D and 3D shapes
Everything we observe in the world has a shape. In the objects we see around us, we can find different basic shapes such as the two-dimensional square, rectangle, and oval, as well as the three-dimensional rectangular prism, cylinder, and sphere. Credit cards, notes and coins, finger rings, photo frames, dart boards, houses, windows, magician's wands, high buildings, flower pots, toys, and balloons are all examples of geometric shapes.
The number of sides or corners of a shape changes from one to another. A side, or vertex, is a straight line that forms part of a shape, and a corner, or vertex, is the point where two sides meet. You're already familiar with the most common shapes, and may not be able to explain the differences between a square and a cube, or a circle and a sphere. In this article you'll start analysing and comparing 2D and 3D shapes, explaining their similarities, differences, and properties.
What are 2D shapes?
2D stands for two-dimensional in 2D shapes. Shapes with two dimensions, such as width and height, are known as 2D shapes. A rectangle or a circle are examples of 2D shapes because they don’t have depth. Basically 2D objects are flat and can't be physically held. We usually refer to dimensions as measurements in a specific direction. Length, width or breadth, depth, and height are examples of dimensions.
Examples of 2D Shapes:
Circle
There is just one bent side of a circle.
A semi-circle has two sides, one curved and one straight.
The full arc of the semi-circle measures 180 degrees.
Triangle
An equilateral triangle is a triangle with each angle measuring 60°.
Any triangle with one right angle is a right-angled triangle.
An irregular triangle is a scalene triangle. All of the sides and angles are unique.
Two sides and two angles of an isosceles triangle are the same.
Quadrilaterals
A square is a regular quadrilateral with 90o angles on all sides.
The diagonals of a kite intersect at right angles and have two sets of equal length sides.
A rectangle is made up of two sets of parallel straight lines, each with a 90° angle.
A rhombus has equal sides and opposite equal angles, as well as two sets of parallel lines.
One pair of parallel lines makes up a trapezium.
Two pairs of parallel lines with opposite equal angles make up a parallelogram.
Image Shows the Illustration of 2D Shapes
3D Shapes
3D means it has three dimensions. So , it isn't flat like a 2D shape. The dimensions of 3D shapes include length, breadth, and depth. Examples of 3D shapes include spheres, cuboids, cubes, square-based pyramids, cylinders, and cones.
Image Shows the Illustration of 3D Shapes
Properties of 3D shapes
A 3D shape will have faces, edges and vertices.
A face on a 3D form is also known as a 'side.' It can be either flat or curved. As a result, a cube has six faces while a sphere has only one.
An edge is the point where two faces or sides of a face meet. You'll find 12 edges on a cube if you count the edges. However, a sphere, such as a ball, has no edges.
A corner is another name for a vertex. This is the point at where the edges meet.
Depending on the shape of the base, the properties of a pyramid can change. A square-based pyramid, for example, has five faces, while a triangle-based pyramid has four.
Differences Between 2D and 3D shapes
You might be confused by the differences between 2D and 3D shapes. There are some ways to measure an object in space. 3D objects can be measured in length, width, and height. 3D shapes, unlike 2D shapes, do not have a flat surface. Means they have depth. Two-dimensional shapes have two dimensions, while three-dimensional shapes have three dimensions. The most important thing for you to understand is that the primary difference between 2D and 3D shapes is their dimension.
Conclusion
2D and 3D shapes are maths topics that fall under geometry. They're covered in other portions of the curriculum as well. In year 3 shapes, you will study, analyse, and compare the qualities of 2D shapes, as well as create patterns using them and solve problems with them. Know how to spot 2D shapes in things like buildings, road signs, and other common objects. This article also gives you an introduction about 3D shapes which will help you in the higher classes.
FAQs on Understanding 2D and 3D Geometric Shapes in Maths
1. What are 2D and 3D geometric shapes?
2D and 3D geometric shapes are figures where 2D shapes have only length and width, while 3D shapes have length, width, and height. 2D shapes are flat and lie on a plane, whereas 3D shapes are solid and occupy space.
Examples:
- 2D shapes: circle, triangle, square, rectangle
- 3D shapes: cube, sphere, cylinder, cone
2. What is the difference between 2D and 3D shapes?
The main difference between 2D and 3D shapes is that 2D shapes have two dimensions, while 3D shapes have three dimensions.
Key differences:
- 2D shapes have area but no volume.
- 3D shapes have both surface area and volume.
- 2D shapes are flat; 3D shapes are solid.
3. What are examples of common 2D geometric shapes?
Common 2D geometric shapes include flat figures such as circle, triangle, square, rectangle, and pentagon.
Properties:
- A circle has no sides or vertices.
- A triangle has 3 sides and 3 angles.
- A square has 4 equal sides and 4 right angles.
4. What are examples of common 3D geometric shapes?
Common 3D geometric shapes include solid figures such as cube, cuboid, sphere, cylinder, and cone.
Properties:
- A cube has 6 square faces, 12 edges, and 8 vertices.
- A sphere has no edges or vertices.
- A cylinder has 2 circular bases and 1 curved surface.
5. What is the formula for the area of common 2D shapes?
The area of common 2D shapes is calculated using specific formulas depending on the shape.
Important area formulas:
- Square: Area = side × side
- Rectangle: Area = length × width
- Triangle: Area = 1/2 × base × height
- Circle: Area = πr²
6. What is the formula for the volume of common 3D shapes?
The volume of common 3D shapes is calculated using formulas based on their dimensions.
Important volume formulas:
- Cube: Volume = side³
- Cuboid: Volume = length × width × height
- Cylinder: Volume = πr²h
- Sphere: Volume = 4/3 πr³
7. How do you calculate the perimeter of a 2D shape?
The perimeter of a 2D shape is the total length of all its sides added together.
Steps to calculate perimeter:
- Add all side lengths.
- For regular shapes, multiply one side by the number of sides.
- Square: Perimeter = 4 × side
- Rectangle: Perimeter = 2(length + width)
8. What are faces, edges, and vertices in 3D shapes?
In 3D geometric shapes, faces are flat surfaces, edges are line segments where faces meet, and vertices are corner points where edges meet.
For example, a cube has:
- 6 faces
- 12 edges
- 8 vertices
9. What is the net of a 3D shape?
A net of a 3D shape is a flat 2D pattern that can be folded to form the solid shape.
For example:
- A cube net consists of 6 connected squares.
- A cylinder net includes 1 rectangle and 2 circles.
10. How are 2D and 3D shapes used in real life?
2D and 3D shapes are used in real life in design, construction, art, and everyday objects.
Examples of real-life applications:
- Buildings use 3D shapes like cubes and cuboids.
- Wheels and coins are circular (2D circle, 3D cylinder).
- Boxes are cuboids with measurable volume.
