Private Sub Command1_Click()
a = Val(InputBox("输入a的长"))
b = Val(InputBox("输入b的长"))
c = Val(InputBox("输入c的长"))
If a + b > c And a + c > b And b + c > a Then
p = (a + b + c) / 2
s = Sqr(p * (p - a) * (p - b) * (p - c))
Print "面积："; s
Else
Print "不是三角形"
End If

End Sub