Using VB.NET PDF SDK
VB.NET PDF Builder: How to draw, add an ellipse shape to PDF file

...
Dim ctx As PDFContext = New PDFContext()
' set figure size: width 600 pixels; height 200 pixels
ctx.SetWidth(New RELength(600, Units.PX))
ctx.SetHeight(New RELength(200, Units.PX))
' draw And fill 3 ellipses
ctx.FillEllipse(New RESolidBrush(New REColor(255, 0, 0)), 150, 10, 180, 80)
ctx.DrawEllipse(New REPen(New REColor(0, 0, 0)), 150, 10, 180, 80)
ctx.FillEllipse(New RESolidBrush(New REColor(0, 255, 0)), 300, 10, 150, 70)
ctx.DrawEllipse(New REPen(New REColor(0, 0, 0), 3.0F), 300, 10, 150, 70)
ctx.DrawEllipse(New REPen(New REColor(0, 0, 255), 5.0F), 240, 75, 120, 100)
Dim figure As Figure = New Figure(ctx)
document.Add(figure)
...

Dim outputFilePath As String = "C:\Sample25.pdf"

Dim document As Document = New Document()
PDFBuildHandler.Create(document, outputFilePath)
' open document
document.Open()
' create Figure
Dim ctx As PDFContext = New PDFContext()
...
...
Dim figure As Figure = New Figure(ctx)
document.Add(figure)
' close document and save to the output file
document.Close()