Line at Angle to Line (3D/2D)
Insert
Wireframe
Line (Part Level)
Insert
Geometry
Line
(Sketch/Sheet
Level)
Use this command to create a line between
two points and at an angle to a reference line, edge, or direction. This
command can be used at the part, sketch and drawling sheet levels. At
the part level, the first point along with the reference line defines
the plane on which the line resides. The second and third points define
the start and end of the line.
At the sketch and drawing sheet levels, the first and second
points are used to define the start and the end of the line. Parallel
and perpendicular lines can also be created using this command at the
sketch and drawing sheet levels.

Specify a reference line. You can select a line or edge or use the Input Option Menu to specify a direction.
Select a point that along with the reference line will determine the plane on which the line resides.
Specify the angle measured from the reference line.
Select a start and end points
for the line. You can drag the line to its end point, enter a distance
from the start point, or right-click to select from the Input Options
Menu.
The line will be constrained at the specified angle to the reference
line.

This command has the same operational sequence as at the Part Level (see above) but with additional options (see below).
Specify a reference line. Move
the cursor over the line until the "at angle" symbol appears
and then select the line. If you middle-click now, the line will be measured
from the horizontal x axis.
You can also create parallel and perpendicular lines by moving the
cursor over the reference line until the appropriate symbol is displayed
and then selecting the line.
Specify the angle measured from the reference line.
Select a start and end points for the line. You can drag the line to its end point, enter a distance from the start point, or right-click to select from the Input Options Menu.
From
Use this option to constrain the beginning
of the line From a point or curve other than the selected start
point. Specify the from point/curve of the line.
To
Use this option to constrain the end of the line To a point or curve other than the selected end point. Specify the "to point/curve" point of the line.