一道vb6.0编程题--求三角形面积

代码如下。
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Private Sub Form_Load()
Do
Dim a As Single, b As Single, c As Single, p As Single, s As Single
a = Val(InputBox("请输入三角形第1条边长"))
If a = -1 Then Exit Do
b = Val(InputBox("请输入三角形第2条边长"))
If b = -1 Then Exit Do
c = Val(InputBox("请输入三角形第3条边长"))
If c = -1 Then Exit Do
p = (a + b + c) / 2
If a >= p Or b >= p Or c >= p Then
MsgBox "不能构成三角形"
Else
s = Sqr(p * (p - a) * (p - b) * (p - c))
MsgBox "面积为" & s
End If
Loop
End
End Sub

Private Sub Command1_Click()
Dim a(3) As Single
Dim c
b = InputBox("请输入三角形的三条边长,以','分隔，如：3,4,5")
c = Split(b, ",")
If UBound(c) < 2 Then
MsgBox "数据不全，请重新输入"
Exit Sub
End If
For i = 0 To 2
If IsNumeric(a(i)) Then
a(i) = Val(c(i))
Else
MsgBox "数据有问题，请重新输入"