API Documentation > CorelDRAW > 2025-v26 > Segment > IVGSegment
Segment.GetTangentAt method
Finds the tangent line to a point on the segment
Syntax:
Function GetTangentAt(Optional ByVal Offset As Double = 0.5, Optional ByVal OffsetType As cdrSegmentOffsetType = cdrParamSegmentOffset) As Double
Parameters:
Name Type Description
Offset
Double
Specifies the offset, in document units, from the beginning of the segment's subpath. 5.
OffsetType
Specifies the offset type of the point on the curve's subpath, and returns cdrSegmentOffsetType.
Remarks:
The GetTangentAt method returns the angle of the tangent at a specified point on a curve segment.
Examples:
The following VBA example draws perpendicular and tangent vectors for several points uniformly distributed along the segments of the selected curve.
Sub Test()
Dim seg As Segment
Dim t As Double
For Each seg In ActiveShape.Curve.Segments
  For t = 0 To 10 Step 2

 MarkPoint seg, t / 10
  Next t
Next seg 
End Sub Private Sub MarkPoint(seg As Segment, t As Double)
Dim x As Double, y As Double
Dim dx As Double, dy As Double
Dim a1 As Double, a2 As Double
seg.GetPointPositionAt x, y, t, cdrRelativeSegmentOffset
a1 = seg.GetTangentAt(t, cdrRelativeSegmentOffset) ' * 3.1415926 / 180
a2 = seg.GetPerpendicularAt(t, cdrRelativeSegmentOffset) * 3.1415926 / 180
dx = 0.5 * Cos(a1)
dy = 0.5 * Sin(a1)
With ActiveLayer.CreateLineSegment(x, y, x + dx, y + dy)
  .Outline.EndArrow = ArrowHeads(1)
End With
dx = 0.5 * Cos(a2)
dy = 0.5 * Sin(a2)
With ActiveLayer.CreateLineSegment(x, y, x + dx, y + dy)
  .Outline.EndArrow = ArrowHeads(1)
End With 
End Sub