tangents- definition geometric constructions a line is a tangent to a circle if it touches the...

Tangents- DefinitionG

eom

etric

Con

stru

ctio

nsG

eom

etric

Con

stru

ctio

ns

A line is a tangent to a circle if it touches

the circle at only one point

Tangents- DefinitionG

eom

etric

Con

stru

ctio

nsG

eom

etric

Con

stru

ctio

ns

Two curves are tangent to each other if the

touch in one and only one place

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Geometric location of tangent point

The tangent point of a straight line and circle will lie at the

intersection of a perpendicular to the straight line that passes

through the center of the circle.

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Geometric location of tangent point

The tangent point of two circles will lie on the circumferences

of both circles and on a straight line connecting the circle

centers

Straight Line Tangents to a Circle from an External point

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

Straight Line Tangents to a Circle from an External point

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

Rr

R-r

R-r

Common Parallel Straight Line Tangents to Two Circles of Radius ‘R’ and ‘r’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

Rr

Common Parallel Straight Line Tangents to Two Circles of Radius ‘R’ and ‘r’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

Rr

R+r

R+r

Common Cross Straight Line Tangents to Two Circles of Radius ‘R’ and ‘r’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

Rr

Common Cross Straight Line Tangents to Two Circles of Radius ‘R’ and ‘r’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

R

R

R

R

Circular Tangent of Radius ‘R’ Between a Point to a Straight Line

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

R R

R

R

R

Circular Tangent of Radius R Between Two Straight Lines at an Angle

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

R

R

R

R+r r

R

R R

Internal Circular Tangent of Radius ‘R’ Between a Straight Line and a Circle of Radius ‘r’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

R

R

R

R-r r

R

R

R

R-r

External Circular Tangent of Radius ‘R’ Between a Straight Line and a Circle of Radius ‘r’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

R+r1

r2

R+r2

R

r1

R+r1

R+r2

R

Internal Circular Tangent of Radius ‘R’ Between Two Circles of Radius ‘r1’ and ‘r2’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

R-r1

r2

R-r2 R

r1

R-r1

R-r2

R

External Circular Tangent of Radius ‘R’ Between Two Circles of Radius ‘r1’ and ‘r2’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

R-r1

r2

R+r2R

r1

R-r1

R+r2

R

Cross Circular Tangent of Radius ‘R’ Between Two Circles of Radius ‘r1’ and ‘r2’

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Tangents- Construction

Basic Sketching Line types

Visible Object – ThickVisible Edges and Outlines

Hidden – ThinHidden detail for like wall

thickness and holes..

Center - Thin centre of a circle, cylindrical

features, or a line of symmetry.

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

1mm3mm

1mm

3mm15-20mm

0.7mmHB

0.3mm2H

0.3mm2H

Line Types An Example:

1. Visible

2. Hidden

3. Center

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Intersection of Lines

Solid Line Intersections

Dashed Line Intersections

GapGeo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Hidden Line ConventionsG

eom

etric

Con

stru

ctio

nsG

eom

etric

Con

stru

ctio

ns

Hidden Line ConventionsG

eom

etric

Con

stru

ctio

nsG

eom

etric

Con

stru

ctio

ns

Centerline Conventions

Extend 5mm

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Lettering : Basic Strokes

Straight Slanted CurvedHorizontal

1 1 2

3

“I” letter “A” letter

1

2

3

4 5

6

“B” letter

Examples:

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions

Lettering : Upper Case & Numerals

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions Gothic vertical style.

Always use capital letters.

Text height 3~5 mm.

Space between lines of text is about of text height.

Lettering : Rules

Space between words equal to the space required for

writing a letter “O”.

Example:

ALL DIMENSIONS ARE INMILLIMETERS

O O OO UNLESS

OTHERWISE SPECIFIED.O

85

R100

R85

85

R100

R85

R70

R70

R70

R70

Tangents- CW 1G

eom

etric

Con

stru

ctio

nsG

eom

etric

Con

stru

ctio

ns

30200

140

80

R=44

R=18

R=16+19=35

R=16

R=8

R=22-5=17R=22

+5=2

7

R=19

R=18+22=40

R=44+22=66

R=19

R=19

Geo

met

ric C

onst

ruct

ions

Geo

met

ric C

onst

ruct

ions