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# Converting the sine of an angle to degrees, minutes, and seconds

J

#### JungleJim74

I am using VS2003 Professional and am trying to display the other two angles
of a right triangle in degrees, minutes, and seconds. This is easy enough to
do with my desktop calculator but I am having difficulty doing it in DOTNET
code. I find the sine of an angle as .6157548327167 which is the sine of an
angle a little over 38 degrees. How do I get this to 38 degrees ? minutes ?
seconds? Thanks in advance for any help and have a good day.
--
JungleJim74

## System One

H

#### Hans Kesting

It happens that JungleJim74 formulated :

> I am using VS2003 Professional and am trying to display the other two angles
> of a right triangle in degrees, minutes, and seconds. This is easy enough to
> do with my desktop calculator but I am having difficulty doing it in DOTNET
> code. I find the sine of an angle as .6157548327167 which is the sine of an
> angle a little over 38 degrees. How do I get this to 38 degrees ? minutes ?
> seconds? Thanks in advance for any help and have a good day.
To go from the sine of an angle to it's value, use the Math.Asin()
method. This will return a value in radians. Note: there is also a
Math.Acos() method that starts with the cosine.
There are "pi" radians in 180 degrees, so you will have to divide the
answer by Math.PI and multiply by 180.
There is no built-in method that displays this number in degress,
minutes and seconds so you will have to calculate that yourself.
The Math.Truncate() method could help here.

For more methods, see
http://msdn.microsoft.com/en-us/library/system.math.aspx

Hans Kesting

## System One

A

#### Andrew Morton

Andrew Morton wrote:

> Use Math.Asin to get the angle in radians and then use google to find
> the conversion.
>
> http://www.freevbcode.com/ShowCode.asp?ID=8179
Or if you were using a later version of VS, you could do the conversion like

Dim a As Double = Math.Asin(0.06316308504476903) * 180.0 / Math.PI
Dim d As Double = Math.Truncate(a)
Dim t As New TimeSpan(CLng((a - d) * 36000000000.0))
Console.WriteLine("{0} {1} {2}", d, t.Minutes, t.Seconds) ' ->3 37 17

Watch out for negative angles.

Andrew

## System One

J

#### JungleJim74

Re: Converting the sine of an angle to degrees, minutes, and secon

Thank you so much but when I try to use the Function that is shown when I
C:\MyDotNet\DecimalDegreesToDMS\Form1.vb(197): 'Truncate' is not a member of
'System.Math'.
"How do I eliminate this compiler error? TIA
--
JungleJim74

"Andrew Morton" wrote:

> Andrew Morton wrote:

> > Use Math.Asin to get the angle in radians and then use google to find
> > the conversion.
> >
> > http://www.freevbcode.com/ShowCode.asp?ID=8179
>
> Or if you were using a later version of VS, you could do the conversion like
>
> Dim a As Double = Math.Asin(0.06316308504476903) * 180.0 / Math.PI
> Dim d As Double = Math.Truncate(a)
> Dim t As New TimeSpan(CLng((a - d) * 36000000000.0))
> Console.WriteLine("{0} {1} {2}", d, t.Minutes, t.Seconds) ' ->3 37 17
>
> Watch out for negative angles.
>
> Andrew
>
>
>

## System One

F

#### Family Tree Mike

Re: Converting the sine of an angle to degrees, minutes, and secon

JungleJim74 wrote:

> Thank you so much but when I try to use the Function that is shown when I
> click on your link I get an error in my compiler
> C:\MyDotNet\DecimalDegreesToDMS\Form1.vb(197): 'Truncate' is not a member of
> 'System.Math'.
> "How do I eliminate this compiler error? TIA
What version of VS are you using?

--
Mike

## System One

A

#### Andrew Morton

Re: Converting the sine of an angle to degrees, minutes, and secon

"JungleJim74"wrote

> Thank you so much but when I try to use the Function that is shown when I
> click on your link I get an error in my compiler
> C:\MyDotNet\DecimalDegreesToDMS\Form1.vb(197): 'Truncate' is not a member
> of
> 'System.Math'.
> "How do I eliminate this compiler error? TIA
Oh! Math.Truncate appears to not be in .NET 1.1.

Did you know you can get a free version of Visual Basic 2008 Express?
http://www.microsoft.com/express/vb/Default.aspx

Otherwise, you can define

Function truncate(ByVal x As Double) As Integer
If Math.Sign(x) >= 0 Then
Return Math.Floor(x)
Else
Return Math.Ceiling(x)
End If
End Function

HTH

Andrew