Draw a circle with your input style (VB 6)
one command button , one Text is needed. Text box is used for put the straight long method.

Code:
Private Sub Command1_Click() 
Cls 
radius = 800 
PI = 3.14 
total = Val(Text1.Text) + Val(Text2.Text) 
a = Val(Text1.Text) 
a = a / total 
dl = PI * 2 * a 
FillColor = QBColor(3) 
FillStyle = 0 
Circle (1900, 1900), radius, RGB(255, 0, 0), -0.00001, -dl 
FillColor = QBColor(2) 
FillStyle = 2 
Circle (1900, 1900), radius, RGB(0, 0, 255), -dl, -0.00001 
End Sub