Visualising Solid Shapes Grade: 8 Maths

Visualising solid shapes is an important topic that helps you to classify and describe solid shapes from different perspectives along with their properties such as faces, edges, vertices, angles, volume surface area, etc.

In this topic we will learn how to visualise solid shapes along with their properties and differences with respect to 2D shapes. Let’s start by understanding what solid shapes are along with their properties and representations.

Definition

A solid is a three dimension shape that occupies space and has length, breadth and height. Here are some key terms to remember when visualising solid shapes.

Key Terms Related to Solids:

• Face: The face of a solid is the flat or curved surface of a three-dimensional shape. For example, a cube has 6 faces, a cylinder has 2 flat faces and 1 curved face.

• Edge: Edge of a solid is a line segment where two faces meet. A cube has 12 edges.

• Vertex: Vertex of a solid is a point where three or more edges meet. A cube has 8 vertices.
  
  

Difference Between Two-Dimensional and Three Dimensional Shapes:

• 2D shapes have only length and breadth (e.g., square, circle, triangle). They lie flat on a plane.

• 3D shapes have length, breadth, and height. They occupy space and have volume.

Euler's formula connects faces, edges, and vertices for polyhedra: F + V − E = 2

Types of Solid Shapes