CalcAngle

Function LineLen(x1, y1, x2, y2)
'This Function will simply give you the length

'of a line using the coordinates of its two

'endpoints.

Dim A, B As Single
A = Abs(x2 - x1)
B = Abs(y2 - y1)
LineLen = Sqr(A ^ 2 + B ^ 2)
End Function

Function Arccos(X As Single)
If X = 1 Then Arccos = 0: Exit Function
Arccos = Atn(-X / Sqr(-X * X + 1)) + 2 * Atn(1)
End Function

Public Function CalcAnAngle(CenterX, CenterY, x2, y2, x3, y3)
'This Function will take three coordinates and

'automagically turn them into an angle.

'The angle is the one located at CenterX, CenterY

'For example:

'/ X2,Y2

'/

' /

' < CenterX,CenterY

' \

'\

'\ X3,Y3

'CalcAnAngle will return the angle, In degrees,

'of the center vertex.

On Error Resume Next
Dim SideA, SideB, SideC As Single
SideC = lineLen(CenterX, CenterY, x2, y2)
SideB = lineLen(CenterX, CenterY, x3, y3)
SideA = lineLen(x3, y3, x2, y2)
a = Arccos((SideA ^ 2 - SideB ^ 2 - SideC ^ 2) / (SideB * SideC * -2))
CalcAnAngle = a * (180 / 3.141)
'VB seems To like to work In confusing units

'called Radians instead of good ol' degrees.

'Multiplying by (180 / 3.141) converts radians

'to degrees.

End Function

Inputs:
Three sets of coordinates: A center point, and the ends
of two lines coming from the center.

Returns:The angle of the vertex in degrees