 # Question: What Is Projection Line In Engineering Drawing?

## What is projection and its type?

Projection are defined as mapping of three-dimensional points to a two-dimensional plane.

There are two type of projection parallel and perspective.

1.

Parallel Projection use to display picture in its true shape and size.

When projectors are perpendicular to view plane then is called orthographic projection..

## Which line is used for projection line?

Type B lines are dimension lines and are used for dimensioning, projecting, extending, or leaders.

## What is Fischer projection formula?

A Fischer projection or Fischer projection formula is a convention used to depict a stereoformula in two dimension without destroying the stereochemical information, i.e., absolute configuration, at chiral centers.

## What is 1st and 3rd angle projection?

To get the first angle projection, the object is placed in the first quadrant meaning it’s placed between the plane of projection and the observer. For the third angle projection, the object is placed below and behind the viewing planes meaning the plane of projection is between the observer and the object.

## What are the two main types of projection?

There are two main types of projection:1)Parallel and Convergent2)Perspective and Parallel3)Parallel and Orthographic4)Station-point and Perspective5)NULL

## How do you solve projection lines?

SOLUTION STEPS:- Draw xy line, one projector and locate a’ 10 mm above xy. Draw locus 100 mm below xy for points b & b1 Draw loci for VT and HT, 30 mm & 45 mm below xy respectively. Take 450 angle from a’ and extend that line backward to locate h’ and VT, & Locate v on xy above VT. Locate HT below h’ as shown.

## What is projection line in civil engineering?

The figure or view formed by joining, in correct sequence, the points at which these lines meet the plane is called the Projection of the object. The lines or rays drawn from the object to the plane are called Projectors. The transparent plane on which the projections are drawn is known as Plane of Projection.

## What are the 3 planes of projection?

[FIGURE 3-2] Projections of the point are made onto three of the surfaces that make up the box: the top or “H” (horizontal) plane, the front or “F” (frontal) plane, and the right side or “P” (profile) plane.

## What is projection in engineering drawing?

Graphical projection is a protocol, used in technical drawing, by which an image of a three-dimensional object is projected onto a planar surface without the aid of numerical calculation.

## What is a hidden line?

A hidden line, also known as a hidden object line is a medium weight line, made of short dashes about 1/8” long with 1/16”gaps, to show edges, surfaces and corners which cannot be seen. Sometimes they are used to make a drawing easier to understand. Often they are omitted in an isometric view.

## What is projection of a point?

The projection of a point is its shadow on the paper sheet. The shadow of a point on the paper sheet is this point itself (idempotency). … The projection parallel to a direction D, onto a plane or parallel projection: The image of a point P is the intersection with the plane of the line parallel to D passing through P.

## How do you calculate a projection?

To forecast sales, multiply the number of units by the price you sell them for. Create projections for each month. Your sales forecast will show a projection of \$12,000 in car wash sales for April. As the projected month passes, look at the difference between expected outcomes and actual results.

## What is 1st angle of projection?

First angle projection is a method of creating a 2D drawing of a 3D object. … This is important information for the person interpreting the drawing because if you examine the diagram below you will note that in first angle orthographic projection: the view from the front is in the middle.

## What is the projection of straight line?

Straight lines in special positions A line parallel to the horizontal plane Π1 is called horizontal (level) line and all its points have the same distance to the horizontal plane, i.e. have the same z-coordinate. Therefore, the vertical projection of that line is parallel to the ground line x.

## What is projection of a line?

Projection lines. Projection lines are extensions of lines that assist in 2D drawing. You can use projection lines to help you create new geometry, and any constraints you create with them remain active even after you turn projection lines off.

## How do you draw a projection of line in engineering graphics?

PROBLEM 1:- A Line AB, 90 mm long, is inclined to H.P. by 30° and inclined to V.P. by 45º. The line is in first quadrant with Point A 15 mm above H.P. and 25 mm in front of V.P. Draw the projection of line AB. 13. PROJECTION OF LINES SH 1132 Engineering Graphics F.Y. B. Tech.

## What is projection formula?

: a perspective formula projected so as to represent it in two dimensions — compare structural formula.