坐标反算

代码说明：

Dim pb As Double    Dim ds As Double    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click        Dim x1 As Double        Dim y1 As Double        Dim x2 As Double        Dim y2 As Double     "定义起点和终点坐标为双精度浮点型        Dim s As Double     "定义距离为双精度浮点型        Dim d As Integer     "定义度为整形        Dim