RBSE Solutions Class 8 Maths Chapter 8 Visualization of Solids More Ques

Page No: 95

Some figures are given below. Answer the given question after seeing each figure sincerely.

Question 1. What is the shape of all faces of cube?
Answer: All the faces of a cube are square in shape. Cubes are known for their perfect symmetry, where all sides are equal.
In simple words: All sides of a cube look like squares.

🎯 Exam Tip: Remember that a cube is a special type of cuboid where all faces are identical squares.

Question 2. What is the shape of all faces of Cuboid?
Answer: All the faces of a cuboid are rectangular in shape. A cuboid typically has three pairs of identical rectangular faces.
In simple words: The faces of a cuboid are rectangles.

🎯 Exam Tip: Distinguish between a cube (all square faces) and a cuboid (all rectangular faces, which can include squares).

Question 3. What is the shape of plane face of Cylinder?
Answer: A cylinder has two plane faces, and both are circular in shape. These circular faces form the top and bottom of the cylinder, connected by a curved surface.
In simple words: The flat parts of a cylinder are circles.

🎯 Exam Tip: For shapes like cylinders and cones, remember to count both the flat (plane) and curved surfaces.

Fill In The Blanks

Answer: Yes, the values in column (6) (V + F) and column (7) (E + 2) are equal for each shape. This important relationship between the number of Vertices (V), Faces (F), and Edges (E) for any polyhedron is called Euler's formula. It states that \( V + F = E + 2 \). This formula was discovered by the great mathematician Euler and is a fundamental concept in geometry.
In simple words: The numbers in column (6) and column (7) are always the same. This is because of a rule called Euler's formula, which helps us understand how many corners, flat sides, and edges a 3D shape has.

🎯 Exam Tip: Always remember Euler's formula \( V + F = E + 2 \), as it's a key principle for polyhedrons and helps check your calculations for vertices, faces, and edges.

Page No: 99

Question 5. May the expended fig. (Net) of this Cuboid be of other types? Please think.
Answer: Yes, the net of a cuboid can indeed be of other types. The image below shows one such alternative type of net for a cuboid. There are many ways to unfold a 3D shape into a 2D net, as long as all the faces are connected in a way that allows them to fold back into the original solid.
In simple words: Yes, a cuboid can be unfolded in different ways, not just one. The picture shows another possible flat shape that can fold into a cuboid.

🎯 Exam Tip: Practice drawing different nets for cubes and cuboids to understand how they unfold and refold into 3D shapes. There can be multiple correct nets for a single solid.