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POLY ENGINEERING2-3

October 1, 20081. Recreate the following chart in your notebook.2. Place each of the 4 technologies below into the

appropriate column.

Washing Machine

Automobile Fuel Gauge

Fire Sprinkler System

Telegraph

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

AutoCAD is a communication technology tool for creating neat, accurate drawings and designs. Although there are numerous features, we will concentrate on the most important ones.

One of the most important actions within the AutoCAD program is the drawing of straight lines.

Before we learn the LINE command, let’s take a look at how we normally draw lines by hand.

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

Lines are drawn from endpoint to endpoint. We must have a method for determining the location of the endpoints.

There are three main methods for determining the location of line endpoints:

1. Absolute Coordinates

2. Relative Coordinates

3. Polar Coordinates

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

Absolute coordinates are based on the origin (0,0), expressed as an ordered pair x,y. All other points are also expressed in the form x,y and the values of x and y are based on the distance from the origin.

If we desire to draw a line, we must give the location of both endpoints, expressed as an ordered pair x,y where the origin is used as a reference point.

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

Relative coordinates are not based on the origin (0,0). Instead, we use the @ symbol followed by an ordered pair x,y. This means “starting where we are AT, go over (or back) x and up (or down) y.

If we desire to draw a line using relative coordinates, we must give the location of the first endpoint (usually using Absolute coordinates), followed by @x,y for the second endpoint.

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

Polar coordinates are not based on the origin (0,0). Instead, we use the @ symbol followed by an ordered pair r<Q. This means “starting where we are AT, go a distance r at an angle of Q degrees. The ‘less than’ sign (<) is used to represent the word ‘angle’.

If we desire to draw a line using polar coordinates, we must give the location of the first endpoint (usually using Absolute coordinates), followed by @r<Q for the second endpoint.

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

When using Polar coordinates, angles are measured according to the following tradition:

0

90

180

270

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

You will now receive a worksheet to help you understand Absolute, Relative, and Polar Coordinates.

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

Here are 2 examples of how to draw absolute coordinates:

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

Here are 2 examples of how to draw relative coordinates:

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POLY ENGINEERING2-3

Communication TechnologyIntroduction to AutoCAD

Here are 2 examples of how to draw polar coordinates:

Now that you have seen some examples, complete all 6 sections of the worksheet.

Homework

LETTER THIS ASSIGNMENT1. Classify the following as

Radio, T.V., Cell Phone, Internet, GPS, Remote Control2. Explain your classification.3. Analyze the components of each of those 6

communication technologies, including the goal, source, encoder, transmitter, receiver, decoder, storage, retrieval, and destination.

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POLY ENGINEERING2-3