口袋海贼王吧:vb程序设计求三角形面积

1、海伦公式:p为三角形的周长的一半,而a,b,c分别为三角形三边的长度, S=p(p-a)(p-b)(p-c)=[(a+b+c)(a+b-c)(a+c-b)(b+c-a)]/2
2、已知底边和高，计算就简单了
3、已知两边和夹角，先求出第三边，再使用第一项计算
其他的类似。源程序如下：

Option Explicit
Dim A As Double, B As Double, C As Double
Dim Ja As Double, Jb As Double, Jc As Double
Dim S As Double

Private Sub Form_Load()
S = S1(3, 6, 8) '已知三边,求面积
MsgBox "三边:3、6、8，面积是" & S
S = S1(3, 6, C1(3, 6, 30 * 3.142 / 180)) '已知两边和夹角,求面积
MsgBox "两边及夹角:3、6、30，面积是" & S
S = S2(3, 6) '已知底和高,求面积
MsgBox "底和高:3、6，面积是" & S
End Sub

Private Function C1(A As Double, B As Double, Jc As Double) As Double
C1 = Sqr(A * A + B * B - 2 * A * B * Cos(Jc))
End Function

Private Function S1(A As Double, B As Double, C As Double) As Double
S1 = (A + B + C) * (A + B - C) * (A + C - B) * (B + C - A) / 2
End Function

Private Function S2(D As Double, G As Double) As Double
S2 = D * G / 2
End Function