TO DRAW PARALLEL LINE -- To draw a line through a point and parallel to a given straight line

A) To draw a line through a given point, parallel to a given straight line

1. Let AB be the given line and P be the given point at a distance.

2. With centre P any convenient radius, draw an arc CD cutting AB at E.

3. With the same radius, from point E as centre draw an arc cutting AB at F.

4. Point E as centre and radius equals to FP, draw an arc cutting CD at Q.

5. Draw a line connecting PQ, This is the required line parallel to AB.

 

B) To draw a line parallel to, and at a given distance from a straight line

1. Let AB be the given line and R is the given radius.

2. Mark points P and Q on line AB, as far apart as convenient.

3. By taking R as radius draw an arc C from given point P.

4. with same radius draw another arc D from point Q.

5. Draw the line CD, just touching the two arc's, now this becomes the parallel line to the given line AB.

LINES in Drawing

Various types of lines used in general engineering drawing are shown below  

Types of Lines:

Solid Lines:

          These are the most commonly used lines in Engineering Drawing. They represent the edges, surfaces, or Outlines of an object, Solid lines are typically used to depict the visible parts of an object.

Thin Lines:

          These are used for various purposes, such as dimension lines (showing the size of an object), Extension lines (extending a line on an object to aid in dimensioning), and leader lines (connecting a dimension number or note to a feature).

Dashed Lines:

Also known as hidden lines. Dashed lines are used to represent edges or surfaces that are not visible in a particular view. For example, they might show the edges of an object that are hidden behind other parts.

Dotted Lines:

          Often used for center lines or symmetry lines, dotted lines indicate the geometric centre of an object or a part. They can also be used to represent the path of movement for moving parts.

Phantom Lines:

          These are used to indicate alternate positions of a moving part or adjacent positions of related parts.

Centre Lines:

          Parts with holes and symmetrical features can be shown by using centre lines. Symmetry can reduce the number of dimensions in a drawing and make it more visually appealing, making it easier for the reader to comprehend.

Dimension Lines:

          Extension lines are used to describe the data being collected. Two arrow heads separate the extension lines on the dimension line from the measurement above (or inside, as shown in the image).

Cutting plane Lines:

          The cutting plane lines illustrate the path of the cutout in a cutout view. The A-A cutting line may be seen here bringing both types of holes into view.