Drawing connected tangent lines

You can:

• Draw a line that is tangent to a curve, circle, arc, ellipse, elliptical arc; or a line that is perpendicular to the imaginary projection (extension) of the tangent line at this point.
• Draw a line that is collinear or perpendicular to a line segment or an axis.

The contextual edit bars

In the process of drawing

For help on snapping, see Snapping objects.

Starts the Detect Relations Manager.

When selected (absolute Dx and Dy)

Relative Dx and Dy while repositioning the line.

Attributes

• Length. Appears as L in the contextual edit bar and as a read-only Length field in the tabular area.
• Angle. Appears when the line is selected. Appears as Angle in the contextual edit bar and as a read-only field (Data column) in the tabular area.
• Absolute Dx and Dy. Appear as Dx and Dy in the contextual edit bar when the line is selected.
• Relative Dx and Dy. Appear on the contextual edit bar only when you are dragging a line to reposition it. Dx/Dy is the relative horizontal/vertical offset distance between the line's original position and the line's new position as projected on the x-axis and the y-axis. The Dx/Dy value is the Ox/Oy coordinate position of the repositioned line less the proportional Ox/Oy coordinate position of the original line.
• Style. For more about styles, see Formatting styles, colors and templates.
• Id. A system-generated, unique object identification number. Appears in the Id column in the tabular area.

NOTE: For help on how to use the Select Quadrant buttons on the contextual edit bar, see Automatic computation of angles.

Control points

The control points of connected tangent lines are the same as those of regular lines.

Tabular representation

When you have finished drawing a connected tangent line, its object type, Id number, length, angle and style appear in the Objects tab in the tabular area:

The data in the Layers & Objects tab is unavailable for direct editing.

Switching modes: tangent line to tangent arc

You can switch from the mode of drawing a regular line to that of drawing a tangent arc, and vice versa. The reverse action launches the line-drawing mode.

To draw a connected tangent line

1. Do any of the following:

• In the Objects toolbar, click the Connected Tangent Line .
• On the Objects menu, point to Lines, and then click Connected Tangent Line.
• Press CTRL+D+T+L.

2. Draw the starting point of the line: depending on the type of line you want to draw (tangent, perpendicular or collinear), click a point that belongs to a straight- or a curved-line segment.
3. (Optional) Snap the end point of the line to another object or point.
4. Do any of the following:

• Point to where you want the end point to be, and then click. The program connects the two points, constructing a line, respectively, tangent, perpendicular or collinear to the line or curve where its starting point lies.
• In the contextual edit bar, in L enter a value for length and point in the appropriate direction; then either press ENTER or click anywhere in the graphical area. The program draws a line with the specified length (the current position of the mouse does not affect the length) that is, respectively, tangent, perpendicular or collinear to the line or curve where its starting point lies.

Notes

• The procedures for repositioning and modifying a connected tangent line are the same as those for a regular line.
• The angle between the actual connected tangent line and the imaginary projection of the tangent at the starting control point can be, respectively, 0 degrees or 90 degrees (accordingly, 180 degrees, 270 degrees, 360 degrees.)
• You can draw a connected tangent line that is tangent, perpendicular or collinear to an axis line.