# Length or coordinate entry method

As you add each element to the alignment, fill out the fields required for the selected element type.

Line elements

To add a line to the alignment, select Line in the Element field and then select the method to construct the line:

If you select... | Then...
--- | ---
Azimuth and length | Enter the Azimuth and Length to define the line. The End north and End east fields automatically update.
End coordinates | Enter the End north and End east values to define the line. The Azimuth and Length fields automatically update.
Select end point | Enter the Point name. The Azimuth, Length, End north and End east fields automatically update.

If this line is not the first line to be defined, the Azimuth field displays an azimuth calculated from the previous element.

To edit the azimuth, tap next to the Azimuth field and select Edit azimuth. If the element is non tangential the icon at the start of the element is shown in red.

Arc elements

To add an arc to the alignment, select Arc in the Element field and then select the method to construct the arc:

If you select... | Then...
--- | ---
Radius and length | Select the arc direction. Enter the Radius and Length to define the arc. The End north and End east fields automatically update.
Delta angle and radius | Select the arc direction. Enter the Angle and Radius to define the arc. The End north and End east fields automatically update.
Deflection angle and length | Select the arc direction. Enter the Angle and Length to define the arc. The End north and End east fields automatically update.
End coordinates | Enter the End north and End east values to define the arc. The Arc direction, Radius, and Length fields automatically update.
Select end point | Enter the Point name. The Azimuth, Length, End north and End east fields automatically update.
End coordinates and center point | Enter the End north, End east, Center point north and Center point east values to define the arc. If required, select Large arc. The Azimuth, Arc direction, Radius, and Length fields automatically update.
Select end and center points | Enter the End point name and Center point name values to define the arc. If required, select Large arc. The Azimuth, Arc direction, Radius, and Length, End north and End east fields update with the values entered.

For an arc defined by Radius and length, Delta angle and radius or Deflection angle and length, the Azimuth field shows the azimuth as calculated from the previous element. If the element is non tangential the icon at the start of the element is shown in red. To reload the original azimuth, tap next to the Azimuth field and select Restore tangency.

Entry transition/exit transition elements

To add a transition to the alignment:

1. Select Entry transition or Exit transition in the Element field.
2. Select the arc direction.

3. Enter the Start radius, End radius and Length to define the transition.

   The End North and End East fields update automatically.

For more information on supported transition types, see Transitions.

The Azimuth field displays the azimuth as calculated from the previous element. To edit the azimuth, tap next to the Azimuth field and select Edit azimuth. If the element is non tangential the icon at the start of the element is shown in red.

If the transition type is NSW cubic parabola the computed Transistion Xc value is displayed. If the transition is between two arcs the Transistion Xc displayed is the value computed for the common tangent point with the smaller of the two arcs.