RBSE Class 8 Maths Notes Chapter 10 Visualizing Solid Shapes

These comprehensive RBSE Class 8 Maths Notes Chapter 10 Visualizing Solid Shapes will give a brief overview of all the concepts.

RBSE Class 8 Maths Chapter 10 Notes Visualizing Solid Shapes

→ Plane shapes have two measurements like length and breadth and therefore they are called two dimensional shapes (2-D figures) whereas a solid object has three mea-surements like length, breadth, height or depth. Hence, they are called three-diamensional shape (3-D figures).

• 2-D figure: Triangle, Rectangle, Circle, Square etc.
• 3- D figure: Cubes, Cylinder, Cones, Spheres etc.

→ A solid which is made up of polygonal regions called faces is called a polyhedron. Two adjoining faces of a polyhedron meet at an edge which is a line segment. Two adjoining edges of a polyhedron meet at a vertex which is a point. Ex.: Cube, cuboid, prism, pyramid etc. sphere, cone and cylinder etc. are not polyhedrons as their faces are not polygons.

→ Convex Polyhedron: A convex polyhedron is one whose all faces are convex polygons.

→ Regujar Polyhedrons: A polyhedron is said to be regular if its faces are made up of regular polygons and the same number of faces meet at each vertex.

→ Prism: A prism is a polyhedron whose base and top are congruent polygons and whose other faces i.e. lateral faces are parallelograms in shape.

→ Pyramids: A pyramid is a polyhedron whose base is a polygon (of any number of sides) and whose lateral faces are triangles with a common vertex.

→ Euler’s Formula: Leonard Euler had discovered a relationship among the faces, edges and vertices of a polyhedron. It is given by F + V - E = 2
Where F stands for number of faces, V stands for number of vertices and E stands for number of edges.