To Create a Line
1. Click > 
Line. The Snapping References dialog box opens. Use the arrow icon in the dialog box to add any references you want to set up before you sketch.
Line. The Snapping References dialog box opens. Use the arrow icon in the dialog box to add any references you want to set up before you sketch.2. You can sketch the following types of lines continuously as a chain or as individual entities:
◦ Horizontally or vertically between any two points
◦ At an angle measured from the x-axis (0)
◦ Tangent to a curve at its second endpoint
◦ Parallel or perpendicular to a specified line
◦ Normal to a curve
◦ Tangent to an arc or a spline
◦ Tangent to two circles or splines
◦ Tangent to a curve and parallel or normal to a reference line