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CBSE Class 8 Maths Visualizing Solid Shapes Notes And Questions

Hi students, welcome to Amans Maths Blogs (AMB). On this page, you will get the short notes and important question of CBSE Class 8 Chapter 10 Visualizing Solid Shapes. These short notes and important questions are taken from the NCERT text books and other books. If you want to get the NCERT Solution for class 8 Maths Visualizing Solid Shapes Chapter, then click here.  If you need sample questions based on visualizing solid shapes for practice, then you are at right place.

SHAPES

Geometrical figures are known as shapes. There are three types of shapes.

One Dimensional shape: Line

Two Dimensional shape: Rectangle cancel etc.

Three Dimensional shape: Polyhedron etc.

POLYHEDRON

A solid shape bounded by the polygons is called Polyhedron. The plural word for polyhedron are Polyhedron, polyhedrons or polyhedral. Polyhedrons are described by three components

Faces: polygons forming a polyhedron are known as faces.

Edges: the line segments formed by the intersection of two faces of a polyhedron known as Edges.

Vertices: the points of intersection of edges of a polyhedron are known as vertices.

Figure

EULER’S FORMULA

A formula which relates the number of faces (F)the number of vertices (V) and the number of edges (E) of a polyhedron is known as Euler’s Formula. Thus, F + V = E + 2  or   F + V – E = 2.

In cube, F = 6, V = 8, E = 12. Thus, F + V – E = 6 + 8 -12 = 2 Hence, cube is a polyhedron.

The Euler’s formula is only for polyhedrons, not for non- polyhedrons like cylinder cone etc.

NON–POLYHEDRONS

The solids which are not made of polygons are known as Non-polyhedrons.

Example:

Figure

Now polyhedrons are of two types: convex polyhedrons and concave polyhedrons.

CONVEX POLYHEDRONS S CONCAVE POLYHEDRONS

If the line segment joining any two ports on the surfaces of a polyhedron entirely lies aside or on the polyhedron, then it is said to be a convex polyhedron otherwise it is known as concave polyhedron.

Figure 2

REGULAR’S IRREGULAR POLYHEDRONS

A polyhedron is a regular polyhedron if its faces are formed by the regular polygons and the same number of meet at each vertex. otherwise, it is an irregular polyhedron.

Figure 2

PRISM

A prism is a solid whose faces are parallelograms and the ends are congruent parallel two Dimensional’s shapes A prism has both and congruent polygon (two dimensional figures). Now, the prism are of two types.

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