This topic applies to ArcGIS for Desktop Standard and ArcGIS for Desktop Advanced only.
You can use the Tangent Curve COGO tool to add tangent curves any time you are working with a parcel traverse or a set of construction lines. The Tangent Curve COGO tool is useful in that it allows you to create tangent curves regardless of the curve parameters set for the current working plan.
When using the Tangent Curve tool, the tangent line used is the previous line in the parcel traverse or construction grid. So, if for example, you would like to use an existing parcel or construction line as the tangent line and it is not the last line in the grid, you would need to insert a new row for the tangent curve just below the line.
To insert a row in the parcel traverse or construction grid in the Parcel Details dialog box, right-click the row above which you want to add the tangent curve and click Insert Row.
To add a tangent curve using the Tangent Curve COGO tool, click the parcel or construction point that will be the From point of your tangent curve, right-click using the Construction Tool , then click Tangent Curve. The tangent curve is calculated using the previous line in the parcel traverse or construction grid.