engineering drawing - Development, METHOD OF Development, development of surfaces of solids, Development of a Right regular cylinder, Development of a Right Rectangular Prism, Truncated Cylinder.

1. Development of surfaces

2. • A Development is the unfolded or unrolled, flat or
plane figure of a 3-D object.
• Development is a graphical method of obtaining the
area of the surfaces of a solid. When a solid is
opened out and its complete surface is laid on a
plane, the surface of the solid is said to be
developed. The figure thus obtained is called a
development of the surfaces of the solid or simply
development.
DEVELOPMENT

3. The following two methods are mainly employed to obtain the
development of surfaces of solids:
1. Parallel line development: This method is employed to develop the
surfaces of prisms and cylinders. Two parallel lines (called stretch-out
lines) are drawn from the two ends of the solids and the lateral faces
are located between these lines.
2. Radial line development: This method is employed to develop the
surfaces of pyramids and cones. An arc of radius equal to the slant
edge/generator is drawn and the lateral faces/curved face are marked
properly inside the arc.
METHOD OF DEVELOPMENT

4. Examples

5. Development of a Right
Rectangular Prism

6. Development of a Right regular
cylinder

7. Truncated Cylinder

8. Example 1
• PARALLEL LINE DEVELOPMENT
• Example 1: The cube of side 50 mm.
Develop all the faces of the cube.