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Introduction to Solid Shapes

Introduction to Solid Shapes

All two-dimensional figures have only length and breadth.

Lesson Demo

All two-dimensional figures have only length and breadth.

For example, paper has only length and breadth, and hence, it is classified as a plane or two-dimensional figure.

Three-dimensional solid shapes have length, breadth and height.

For example, a biscuit tin is in three-dimensional shape.

Faces:

The flat surfaces that form the skin of solids are called faces.

Edges:

The line segments that form the skeleton of solids are called edges.

Vertices:

The points where three edges meet are called vertices.

The table shows the number of the faces, edges and vertices of some shapes.

 Face (F) Edge (E) Vertex (V) Cylinder 3 2 0 Cone 2 1 1 Triangular pyramid 4 6 4

The net of a three-dimensional solid is a two-dimensional skeleton outline, which, when folded, results in the three-dimensional shape.

Net

solid

Solid shapes can be drawn on a flat surface, which is known as the two-dimensional representation of a three-dimensional solid.

Sketches of solids are of two types: oblique and isometric.

Oblique sketches are drawn on squared paper. They do not have exact dimensions, but still convey all the significant aspects of the appearance of a solid.

Isometric sketches are drawn on dotted or isometric sheets and have the exact measurements of solids.