Triangulation Pattern Development

Question 1

What are 3 types of triangulated fittings?

Answer 1

1. Top Takeoff
2. End Boot
3. Garbage Chut

Question 2

The hypotenuse is a side on what kind of triangle?

Answer 2

Right Angled Triangle

Question 3

What is Pythagorean equation?

Answer 3

a2 + b2 = c2

Question 4

A face line is used when a triangulating _______ fitting.

a. ships ventilator
b. right angled
c. transitional Y-branch
d. top takeoff

Answer 4

c. transitional Y-branch

Question 5

Define : Foreshorten Line

Answer 5

A line that appears to be shorter than it really is.

Question 6

Can the vertical height of a fitting include seams and allowances?

YES or NO

Answer 6

YES

Question 7

Does the face line run 90* to the secondary Y-branch opening?

YES or NO

Answer 7

NO

Question 8

When determining the VH (vertical height) for a pattern, what must be subtracted?

Answer 8

Seams and Allowances

Question 9

Triangulation is described in 2 ways. State one definition.

Answer 9

Finding the length of a hypotenuse using the vertical and horizontal legs of a right triangle.

Question 10

Triangulation is described in 2 ways. State one definition.

Answer 10

Developing the surface of fittings with surfaces that slants at different angles

Question 11

What are the 3 types of pattern development?

Answer 11

1. Triangulation 2. Parallel Line 3. Radial Line

Question 12

In residential furnace replacement, which fitting is used?

Answer 12

Transition fitting is used from the new furnace to the existing plenum and duct work.

Question 13

Define : True Length Lines

Answer 13

Lines that are perpendicular to the viewer’s line of vision.

Question 14

Define : True Length Triangle

Answer 14

Is a right angle triangle whose horizontal leg is equal to the length of the foreshortened line (plan view) and its vertical leg is equal to the vertical height of the fitting (elevation view).

Question 15

Define : Face Line

Answer 15

Is the perpendicular line representing the branch opening for an elbow or Y branch.

Question 16

What are the 3 versons of Pythagorean?

Answer 16

1. c2 = a2 + b2
2. a2 = c2 - b2
3. b2 = c2- a2

Question 17

When labeling a Plan View of a fitting, how do you distinguish one end from another?

Answer 17

Always start in the bottom left hand corner.

Then label clockwise.

• Number are used on the top opening
• Letters are used on the bottom opening

Question 18

Why must a Diagram of the True Lenghts must be drawn?

Answer 18

In order to trianglate the necessary points on the pattern.

Question 19

What are the steps to complete a side of a Transition Fitting, on Center?

Answer 19

1. Located points B and A on pattern baseline. Then bisect B to A with center line.
2. Draw Diagram of True Lenghts. V.H is vertical leg. Horzontal leg step off distance between B-A and 2-1.
3. From Diagram of True Lengths transfer the distance V.H to A-1 to pattern center line starting at base line, moving up. This new point is actual hiegth of fitting.
4. From Plan View, transfer the distance of point 1 to center line to patterns new top horizontal line, swinging from center line. This will give you points 2 and 1 on pattern.
5. Now connect the points with construction lines and label pattern.

Question 20

What is the necessary information that must be labeled on a finished pattern?

Answer 20

• Inside or Outside
• How many required
• Brake or transition lines with direction (in upper case).
• Which View Side

Front / Back or Left / Right

Question 21

What is the least amount of pieces a transiton fitting with 2 flat sides be layed out in?

Answer 21

3 pieces

Question 22

Are rectangle to round on pitch found on flat roofs ?

1. Yes
2. No
3. Only if the roof is 600’ squared or more.
4. Only if the roof is 600’ squared or less.

Answer 22

2. No

Question 23

Rectangle to round offset fittings combine how many fittings ?

1. 2
2. 3
3. 4
4. none of the above.

Answer 23

1. 2

Question 24

Triangulation from elevation uses ___________.

1. elevation and right side view.
2. an elevation view and plan view(s).
3. elevation view, right side view and plan view(s).
4. elevation view only.

Answer 24

2. an elevation view and plan view(s).

Question 25

When the fitting is on center, the work line is always located ___________ from the round opening on the plan view.

Answer 25

half the depth of the retangular opening as seen in plan view

Question 26

When developing a body pattern for a rectangle to round offset with mitered collars, where are the 1/12 spaces taken from?

Answer 26

The curved line on the collar pattern.

Question 27

Should the round collar be developed first or last on a rectangle to round offset ?

Answer 27

First Need curved line to do custom 1/12 spacing.

Question 28

When should the round collar be developed on a rectangle to round on pitch fitting ?

Answer 28

It does not matter.