Visualising solid shapes class 7 notes provided here are one of the most important resources for the students of class 7. These CBSE class 7 notes for chapter 15 will not only help the students to learn the concepts easily but will also help them to revise this topic in a more efficient way. The different topics from this chapter that are included here are-
- What are solid shapes and plane figures?
- Faces, edges, and vertices of a solid shape
- Types of sketches of a solid
- Ways of viewing a solid shape
- Practice Questions
What are Solid Shapes and Plane Figures?
Plane figures are of two dimensions i.e. 2D and they have only length and breadth. On the other hand, solid shapes are three dimensional shapes which means they have height, breadth, and length. A few examples of plane figure are circles, squares, triangles, etc. and examples of solid shapes or 3D shapes are sphere, cuboid, pyramid, etc.
Faces, Edges, and Vertices of a Solid Shape
Faces, edges, and vertices are terms associated with 3D shapes and they refer to as-
- Faces – the flat surfaces of a solid shape are its faces
- Edges – the line segments of a solid shape’s skeleton are its edges
- Vertices – the corner of a solid shape are its vertices
Edges, vertices, and faces of common 3D shapes:
|Cube and Cuboid||8||12||6|
|Prism||6||9||5 (2 triangle + 3 rectangle)|
|Cylinder||0||2||3 (2 circle + 1 curved)|
|Cone||1||1||2 (1 circle + 1 curved)|
Types of Sketches of a Solid
Two types of sketches of a solid shape or 3D shape are possible which are-
- Oblique Sketch – it does not have proportional lengths
- Isometric Sketch – it has proportional lengths
It should be noted that solid shapes can be drawn on papers as a 2D model. This representation of a 3D shape into a 2D shape is known as 2-D representation of a 3-D solid.
Ways of Viewing a Solid Shape
The three most common ways of viewing a solid shape are-
- Slicing of cutting the shape which shows the cross section of the solid
- Observing 2D shadow of a 3D shape
- Visualising the solid shape from front-view, side-view, and top-view
- A cuboid has the dimensions of 5 cm, 3 cm and 2 cm. Draw three different isometric sketches of this cuboid.
- Three cubes having 2 cm edge each are placed side by side to form a cuboid. Sketch an oblique and isometric sketch of this cuboid.
- Write true or false – (i) a cube can cast a shadow in the shape of a hexagon, (ii) a cube can cast a shadow in the shape of a rectangle.
|Sections Of Solids: Slicing And Shadows||Making 3D Shapes Using Nets|
|Faces, Edges and Vertices: 3D Shapes||NCERT Solutions Class 7 Maths Visualising Solid Shapes|
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