Table of contents  
Plane Figures and Solid Shapes  
Faces, Edges and Vertices  
Nets for Building 3D Shapes  
Drawing Solids on a Flat Surface  
Viewing Different Sections of a Solid 
Have you ever looked around your classroom and noticed the different shapes all around you? From the cubes of your classroom blocks to the cylinders of soda cans, solid shapes are everywhere!
But what exactly are these solid shapes, and how do we visualize them?
This picture would be a 2D image because it has only two dimensions: length and width. It's like looking at a flat drawing of your pencil box on a piece of paper.
2D Image
In this chapter, we will explore the fascinating world of solid shapes, also known as 3D shapes. These shapes have depth, width, and height, making them much more interesting than flat shapes! You’ll learn how to identify, describe, and visualize shapes like cubes, spheres, cones, and pyramids.
3D Image
In simple terms, a 2D image is like a flat drawing, and a 3D image is like seeing the real object in front of you.
The table shows the number of the faces, edges and vertices of some shapes.
The net of a threedimensional solid is a twodimensional skeleton outline, which, when folded, results in the threedimensional shape. Net is used for making 3D shapes.
Nets of 3D Shapes
Example to Practice: Match the following nets with appropriate solids.
Solution:
(a) → (ii)
(b) → (iii)
(c) → (iv)
(d) → (i)
There are two techniques to create the illusion, of threedimensionality when drawing solid shapes on a flat surface, such as paper.
There are many methods to view different sections of a solid:
(a) Slicing and Cutting: This method reveals the inside of a solid by slicing it into crosssections.
(b) Shadow Casting: This technique creates a twodimensional representation of a threedimensional object by casting its shadow. The resultant shape depends upon the side of the object where we throw the light.If we throw the light on the cylinder from its circular side then we will get the image of a circle.
If we throw the light on the cylinder while it is on standing position then its shadow will be rectangular in shape.
(c) Viewing from Different Angles: Observing a solid from various perspectives, such as front, side, and top views, offers valuable insights into its shape and structure.
Example: Different viewpoints of a building are illustrated below.
Remember, the skills you’ve developed in visualizing solid shapes are not just important in math; they also play a crucial role in fields like architecture, engineering, and art. So, keep observing the world around you and think about how these shapes connect to everything you see.
By building a strong foundation in understanding solid shapes, you're preparing yourself for more complex mathematical concepts in the future. So, let your curiosity guide you, and continue to explore the exciting shapes that make up our vibrant world!
76 videos345 docs39 tests

1. What are some examples of plane figures and solid shapes? 
2. What is the difference between faces, edges, and vertices of 3D shapes? 
3. How can nets be used to build 3D shapes? 
4. What is the purpose of drawing solids on a flat surface? 
5. How can different sections of a solid be viewed? 

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