Несовпадение типов (график) - VB

Const pi = 3.14
Dim x1, x2, x3, y1, y2, ab, bc, ac, r, p, S1, S2, S As Integer
 
Private Sub Command1_Click()
x1 = Int(Val(Text1.Text))
x2 = Int(Val(Text2.Text))
x3 = Int(Val(Text3.Text))
y1 = Int(Val(Text4.Text))
y2 = Int(Val(Text5.Text))
S = Int(Val(Text6.Text))
ab = Sqr((x2 - x1) * 2 + (y2 - y1) * 2)
bc = Sqr((x3 - x2) * 2 + (y1 - y2) * 2)
ac = Sqr((x3 - x1) * 2)
p = (ab + bc + ac) / 2
S1 = Sqr(p * (p - ab) * (p - bc) * (p - ac))
r = ac / 2
S2 = (pi * r ^ 2) / 2
 S = S1 + S2
MsgBox S
End Sub