Math.PI Field

Represents the ratio of the circumference of a circle to its diameter, specified by the constant, π.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

Syntax

'Declaration
Public Const PI As Double
public const double PI

Remarks

The value of this field is 3.14159265358979323846.

Examples

The following code sample uses PI to assist in the computation of the inner angles of a given trapezoid.

'The following class represents simple functionality of the trapezoid.
Class Example

   Private m_longBase As Double
   Private m_shortBase As Double
   Private m_leftLeg As Double
   Private m_rightLeg As Double

   Public Sub New(ByVal longbase As Double, ByVal shortbase As Double, ByVal leftLeg As Double, ByVal rightLeg As Double)
      m_longBase = Math.Abs(longbase)
      m_shortBase = Math.Abs(shortbase)
      m_leftLeg = Math.Abs(leftLeg)
      m_rightLeg = Math.Abs(rightLeg)
   End Sub

   Private Function GetRightSmallBase() As Double
      GetRightSmallBase = (Math.Pow(m_rightLeg, 2) - Math.Pow(m_leftLeg, 2) + Math.Pow(m_longBase, 2) + Math.Pow(m_shortBase, 2) - 2 * m_shortBase * m_longBase) / (2 * (m_longBase - m_shortBase))
   End Function

   Public Function GetHeight() As Double
      Dim x As Double = GetRightSmallBase()
      GetHeight = Math.Sqrt(Math.Pow(m_rightLeg, 2) - Math.Pow(x, 2))
   End Function

   Public Function GetSquare() As Double
      GetSquare = GetHeight() * m_longBase / 2
   End Function

   Public Function GetLeftBaseRadianAngle() As Double
      Dim sinX As Double = GetHeight() / m_leftLeg
      GetLeftBaseRadianAngle = Math.Round(Math.Asin(sinX), 2)
   End Function

   Public Function GetRightBaseRadianAngle() As Double
      Dim x As Double = GetRightSmallBase()
      Dim cosX As Double = (Math.Pow(m_rightLeg, 2) + Math.Pow(x, 2) - Math.Pow(GetHeight(), 2)) / (2 * x * m_rightLeg)
      GetRightBaseRadianAngle = Math.Round(Math.Acos(cosX), 2)
   End Function

   Public Function GetLeftBaseDegreeAngle() As Double
      Dim x As Double = GetLeftBaseRadianAngle() * 180 / Math.PI
      GetLeftBaseDegreeAngle = Math.Round(x, 2)
   End Function

   Public Function GetRightBaseDegreeAngle() As Double
      Dim x As Double = GetRightBaseRadianAngle() * 180 / Math.PI
      GetRightBaseDegreeAngle = Math.Round(x, 2)
   End Function

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim trpz As Example = New Example(20, 10, 8, 6)
      outputBlock.Text += String.Format("The trapezoid's bases are 20.0 and 10.0, the trapezoid's legs are 8.0 and 6.0") & vbCrLf
      Dim h As Double = trpz.GetHeight()
      outputBlock.Text &= "Trapezoid height is: " + h.ToString() & vbCrLf
      Dim dxR As Double = trpz.GetLeftBaseRadianAngle()
      outputBlock.Text &= "Trapezoid left base angle is: " + dxR.ToString() + " Radians" & vbCrLf
      Dim dyR As Double = trpz.GetRightBaseRadianAngle()
      outputBlock.Text &= "Trapezoid right base angle is: " + dyR.ToString() + " Radians" & vbCrLf
      Dim dxD As Double = trpz.GetLeftBaseDegreeAngle()
      outputBlock.Text &= "Trapezoid left base angle is: " + dxD.ToString() + " Degrees" & vbCrLf
      Dim dyD As Double = trpz.GetRightBaseDegreeAngle()
      outputBlock.Text &= "Trapezoid left base angle is: " + dyD.ToString() + " Degrees" & vbCrLf
   End Sub

End Class

/// <summary>
/// The following class represents simple functionality of the trapezoid.
/// </summary>
class Example
{
   private double m_longBase;
   private double m_shortBase;
   private double m_leftLeg;
   private double m_rightLeg;

   public Example(double longbase, double shortbase, double leftLeg, double rightLeg)
   {
      m_longBase = Math.Abs(longbase);
      m_shortBase = Math.Abs(shortbase);
      m_leftLeg = Math.Abs(leftLeg);
      m_rightLeg = Math.Abs(rightLeg);
   }

   private double GetRightSmallBase()
   {
      return (Math.Pow(m_rightLeg, 2.0) - Math.Pow(m_leftLeg, 2.0) + Math.Pow(m_longBase, 2.0) + Math.Pow(m_shortBase, 2.0) - 2 * m_shortBase * m_longBase) / (2 * (m_longBase - m_shortBase));
   }

   public double GetHeight()
   {
      double x = GetRightSmallBase();
      return Math.Sqrt(Math.Pow(m_rightLeg, 2.0) - Math.Pow(x, 2.0));
   }

   public double GetSquare()
   {
      return GetHeight() * m_longBase / 2.0;
   }

   public double GetLeftBaseRadianAngle()
   {
      double sinX = GetHeight() / m_leftLeg;
      return Math.Round(Math.Asin(sinX), 2);
   }

   public double GetRightBaseRadianAngle()
   {
      double x = GetRightSmallBase();
      double cosX = (Math.Pow(m_rightLeg, 2.0) + Math.Pow(x, 2.0) - Math.Pow(GetHeight(), 2.0)) / (2 * x * m_rightLeg);
      return Math.Round(Math.Acos(cosX), 2);
   }

   public double GetLeftBaseDegreeAngle()
   {
      double x = GetLeftBaseRadianAngle() * 180 / Math.PI;
      return Math.Round(x, 2);
   }

   public double GetRightBaseDegreeAngle()
   {
      double x = GetRightBaseRadianAngle() * 180 / Math.PI;
      return Math.Round(x, 2);
   }

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      Example trpz = new Example(20.0, 10.0, 8.0, 6.0);
      outputBlock.Text += String.Format("The trapezoid's bases are 20.0 and 10.0, the trapezoid's legs are 8.0 and 6.0") + "\n";
      double h = trpz.GetHeight();
      outputBlock.Text += "Trapezoid height is: " + h.ToString() + "\n";
      double dxR = trpz.GetLeftBaseRadianAngle();
      outputBlock.Text += "Trapezoid left base angle is: " + dxR.ToString() + " Radians" + "\n";
      double dyR = trpz.GetRightBaseRadianAngle();
      outputBlock.Text += "Trapezoid right base angle is: " + dyR.ToString() + " Radians" + "\n";
      double dxD = trpz.GetLeftBaseDegreeAngle();
      outputBlock.Text += "Trapezoid left base angle is: " + dxD.ToString() + " Degrees" + "\n";
      double dyD = trpz.GetRightBaseDegreeAngle();
      outputBlock.Text += "Trapezoid left base angle is: " + dyD.ToString() + " Degrees" + "\n";
   }
}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

See Also

Reference