已知两点(一条直线),做直角三角形.

兰州人

2. Sub ll()
3.   Dim p0(2) As Double, p1(2) As Double, Pp(2) As Double
4.   Dim R, rLen
5.   p0(0) = -20
6.   p0(1) = 50
7.   p1(0) = 0
8.   p1(1) = 0
9.   R = 10
10.   rLen = Sqr((p0(0) - p1(0)) ^ 2 + (p0(1) - p1(1)) ^ 2)
11.   Dim objLine As AcadLine
12.   Set objLine = ThisDrawing.ModelSpace.AddLine(p1, p0)
13.   ThisDrawing.Regen acActiveViewport
14.   Dim Alfa1, Alfa2
15.   With objLine
16.     Alfa1 = .Angle
17.     Alfa2 = ACos(R / .Length)
18.     Debug.Print Alfa1 * 180 / 3.1415926, Alfa2 * 180 / 3.1415926
19.     Pp(0) = R * Cos(Alfa1 + Alfa2)
20.     Pp(1) = R * Sin(Alfa1 + Alfa2)
21.   End With
22.   With ThisDrawing.ModelSpace
23.     Set objLine = .AddLine(Pp, p0)
24.     objLine.color = acGreen
25.     Set objLine = .AddLine(Pp, p1)
26.     objLine.color = acRed
27.   End With
28.   
29. End Sub
30. Function ACos(x) As Double
31.    ACos = Atn(Sqr(1 - x * x) / x) '+ 4 * Atn(1)
32. End Function

Sub ll()   Dim p0(2) As Double, p1(2) As Double, Pp(2) As Double   Dim R, rLen   p0(0) = -20   p0(1) = 50   p1(0) = 0   p1(1) = 0   R = 10   rLen = Sqr((p0(0) - p1(0)) ^ 2 + (p0(1) - p1(1)) ^ 2)   Dim objLine As AcadLine   Set objLine = ThisDrawing.ModelSpace.AddLine(p1, p0)   ThisDrawing.Regen acActiveViewport   Dim Alfa1, Alfa2   With objLine     Alfa1 = .Angle     Alfa2 = ACos(R / .Length)     Debug.Print Alfa1 * 180 / 3.1415926, Alfa2 * 180 / 3.1415926     Pp(0) = R * Cos(Alfa1 + Alfa2)     Pp(1) = R * Sin(Alfa1 + Alfa2)   End With   With ThisDrawing.ModelSpace     Set objLine = .AddLine(Pp, p0)     objLine.color = acGreen     Set objLine = .AddLine(Pp, p1)     objLine.color = acRed   End With    End Sub Function ACos(x) As Double    ACos = Atn(Sqr(1 - x * x) / x) '+ 4 * Atn(1) End Function