A line is the simplest entity you can add to a drawing. A line consists of two points: a start point and an endpoint. A series of lines can be connected, but each line segment is considered a separate line entity. The drawing database records the start and end points of the line, the colour, linetype, line thickness and layer that the line is on. 

In gCADPlus, when a command like LINE prompts you for a point, you can use the pointing device (your mouse) to specify a point by clicking, or you can enter a coordinate value on the command line. You can enter coordinates as either Cartesian or polar coordinates. (see page on coordinate entry). To use coordinates to specify a point, enter an X value and a Y value separated by a comma (X,Y). [This is the same way coordinates are entered in AutoCAD] 

Tip: If you have used the LINE command as the last command, it will also appear at the pop up menu activated by the right mouse button.

About real world units

The line might represent a boundary or paved area. The line represents something in the real world. All gCADPlus drawings are a model of the real world site and drawn full size, so the line must be accurately placed using units you work with. In the USA, that would commonly be feet (decimal feet rather than feet and inches) and  millimeters in the metric system.

Occasionally a survey firm might produce a base plan in meters and you will need to convert those drawings to your units (see the later discussion on the use of the SCALE command).

Common (simple straight forward) entry method to draw a line 
  1. Make sure that the Polar option is on (click on the polar button in the status (bottom) line.
  2. Start the line command, either by typing L and ENTER or select from toolbar or drop down Draw menu
  3. Set the start point of the line with a left click of the mouse.
  4. Move the cursor in the direction you want to draw. Because polar is on, you can only move horizontally, vertically or at an angle of 45 degrees.
  5. Type the length of the line, ENTER and right click to finish.


Drawing a line with relative coordinates

To specify a relative coordinate, precede the coordinate with an @ symbol. For example, the coordinate @3,4 specifies a point 3 units along the X axis and 4 units along the Y axis from the last point specified.

Draw a line using polar coordinates

To enter a polar coordinate, enter a distance and an angle separated by an angle bracket (<). For example, to specifystart point that is at a distance of 1 unit from the previous point and 
at an angle of 45 degrees, enter @1<45.

The importance of the angle setting

By default, angles increase in the counterclockwise direction and decrease in the clockwise direction. To move clockwise, enter a negative value for the angle. For example, entering 1<315 is the same as entering 1<-45.

Polar coordinates are either absolute (measured from the origin) or relative to the previous point. To specify a relative coordinate, precede the coordinate with an @ symbol.

Imperial [USA] system

gCADPlus works well in the Imperial (feet and inches environment). Distance are entered as decimal feet, so a line representing the wall of a courtyard 27 ft 9 inches long, would be entered as 27.75; the distance; 40.75 corresponds to 40 feet 9 inches and so on.

Here is a link to download an Excel calculator that converts measurements in feet and inches to decimal feet for use in gCADPlus. The screen grab below shows the calculator in operation. We suggest that you have the spreadsheet running for quick conversions while you are working with gCADPlus in the Imperial system.