IS 15021: Part 2: 2001 is standard for Orthographic representations. IS 11065: Part 2: 1985 is standard for Di-metric projection. IS 11065: Part 1: 1984 is standard for Isometric projection. IS 10711: 2001/ISO 5457: 1999 is standard for Sizes and Layout of Drawing Sheets.

In third angle projection projections of object is taken by placing object in 3rd quadrant. If object?s surface is coinciding vertical plane which indirectly saying distance from vertical plane is zero so top view of that object touches reference line.

A Square pyramid have base of square which is resting on vertical plane as said above so side views, top view and bottom view gives triangle and front view and back view gives square.

Given egg is placed vertical to horizontal plane front view and side view will be same and it might be conical, oval or elliptical etc. top view always be circle. That?s why egg boxes are made impression of semi spheres.

In third angle projection top view of object is above front view and n come side views to left and right of front view and n back view which can eir be kept on ends of side views but as standard notation it is placed on right side of right side view.

Explanation:

Projection

• If straight lines are drawn from various points on contour of an object to meet a plane, object is said to be projected on that plane.
• The figure formed by joining, in correct sequence points at which lines meet plane is called a projection of that object.
• The lines from object to plane are called projectors.
• For purpose of construction, a drawing should show true shapes of all parts of an object toger with ir sizes.
• Orthographic projection is universally adopted for this purpose.
• By this method, description of object regarding its shape and size is conveyed in definite and unmistakable terms so that it can be constructed precisely.
• The object is shown in two or more views, obtained by looking at it from different angles and arranged in a definite manner.

By viewing in mutual perpendicular planes- Vertical plane, horizontal plane, profile plane which indirectly gives us front view in x-direction, top-view in y ?direction and thickness in z-direction which are mutually perpendicular. Ortho means perpendicular.

The front view will be shown on vertical plane, top view will be represented on horizontal plane and side view will be represents on profile plane. The top view gives thickness and width of object.

In orthographic projection, projectors are parallel to each or and also perpendicular to plane but in oblique projection, projectors are inclined to plane of projection and projectors are parallel to each or.

Given direction is anti-clockwise direction so angle in 270 degrees if it is given clockwise direction angle should be 90 degrees since given planes are consecutive planes in planes of projection.