Math.Acos(Double) Method
Definition
Important
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Returns the angle whose cosine is the specified number.
public:
static double Acos(double d);
public static double Acos (double d);
static member Acos : double -> double
Public Shared Function Acos (d As Double) As Double
Parameters
- d
- Double
A number representing a cosine, where d
must be greater than or equal to -1, but less than or equal to 1.
Returns
An angle, θ, measured in radians, such that 0 ≤ θ ≤ π.
-or-
NaN if d
< -1 or d
> 1 or d
equals NaN.
Examples
The following example uses the Acos method to assist in the computation of the inner angles of a given trapezoid.
/// <summary>
/// The following class represents simple functionality of the trapezoid.
/// </summary>
using namespace System;
public ref class MathTrapezoidSample
{
private:
double m_longBase;
double m_shortBase;
double m_leftLeg;
double m_rightLeg;
public:
MathTrapezoidSample( 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 ) );
}
double GetSquare()
{
return GetHeight() * m_longBase / 2.0;
}
double GetLeftBaseRadianAngle()
{
double sinX = GetHeight() / m_leftLeg;
return Math::Round( Math::Asin( sinX ), 2 );
}
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 );
}
double GetLeftBaseDegreeAngle()
{
double x = GetLeftBaseRadianAngle() * 180 / Math::PI;
return Math::Round( x, 2 );
}
double GetRightBaseDegreeAngle()
{
double x = GetRightBaseRadianAngle() * 180 / Math::PI;
return Math::Round( x, 2 );
}
};
int main()
{
MathTrapezoidSample^ trpz = gcnew MathTrapezoidSample( 20.0,10.0,8.0,6.0 );
Console::WriteLine( "The trapezoid's bases are 20.0 and 10.0, the trapezoid's legs are 8.0 and 6.0" );
double h = trpz->GetHeight();
Console::WriteLine( "Trapezoid height is: {0}", h.ToString() );
double dxR = trpz->GetLeftBaseRadianAngle();
Console::WriteLine( "Trapezoid left base angle is: {0} Radians", dxR.ToString() );
double dyR = trpz->GetRightBaseRadianAngle();
Console::WriteLine( "Trapezoid right base angle is: {0} Radians", dyR.ToString() );
double dxD = trpz->GetLeftBaseDegreeAngle();
Console::WriteLine( "Trapezoid left base angle is: {0} Degrees", dxD.ToString() );
double dyD = trpz->GetRightBaseDegreeAngle();
Console::WriteLine( "Trapezoid left base angle is: {0} Degrees", dyD.ToString() );
}
/// <summary>
/// The following class represents simple functionality of the trapezoid.
/// </summary>
using System;
namespace MathClassCS
{
class MathTrapezoidSample
{
private double m_longBase;
private double m_shortBase;
private double m_leftLeg;
private double m_rightLeg;
public MathTrapezoidSample(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);
}
static void Main(string[] args)
{
MathTrapezoidSample trpz = new MathTrapezoidSample(20.0, 10.0, 8.0, 6.0);
Console.WriteLine("The trapezoid's bases are 20.0 and 10.0, the trapezoid's legs are 8.0 and 6.0");
double h = trpz.GetHeight();
Console.WriteLine("Trapezoid height is: " + h.ToString());
double dxR = trpz.GetLeftBaseRadianAngle();
Console.WriteLine("Trapezoid left base angle is: " + dxR.ToString() + " Radians");
double dyR = trpz.GetRightBaseRadianAngle();
Console.WriteLine("Trapezoid right base angle is: " + dyR.ToString() + " Radians");
double dxD = trpz.GetLeftBaseDegreeAngle();
Console.WriteLine("Trapezoid left base angle is: " + dxD.ToString() + " Degrees");
double dyD = trpz.GetRightBaseDegreeAngle();
Console.WriteLine("Trapezoid left base angle is: " + dyD.ToString() + " Degrees");
}
}
}
open System
/// The following class represents simple functionality of the trapezoid.
type MathTrapezoidSample(longbase, shortbase, leftLeg, rightLeg) =
member _.GetRightSmallBase() =
(Math.Pow(rightLeg, 2.) - Math.Pow(leftLeg, 2.) + Math.Pow(longbase, 2.) + Math.Pow(shortbase, 2.) - 2. * shortbase * longbase) / (2. * (longbase - shortbase))
member this.GetHeight() =
let x = this.GetRightSmallBase()
Math.Sqrt(Math.Pow(rightLeg, 2.) - Math.Pow(x, 2.))
member this.GetSquare() =
this.GetHeight() * longbase / 2.
member this.GetLeftBaseRadianAngle() =
let sinX = this.GetHeight() / leftLeg
Math.Round(Math.Asin sinX,2)
member this.GetRightBaseRadianAngle() =
let x = this.GetRightSmallBase()
let cosX = (Math.Pow(rightLeg, 2.) + Math.Pow(x, 2.) - Math.Pow(this.GetHeight(), 2.))/(2. * x * rightLeg)
Math.Round(Math.Acos cosX, 2)
member this.GetLeftBaseDegreeAngle() =
let x = this.GetLeftBaseRadianAngle() * 180. / Math.PI
Math.Round(x, 2)
member this.GetRightBaseDegreeAngle() =
let x = this.GetRightBaseRadianAngle() * 180. / Math.PI
Math.Round(x, 2)
let trpz = MathTrapezoidSample(20., 10., 8., 6.)
printfn "The trapezoid's bases are 20.0 and 10.0, the trapezoid's legs are 8.0 and 6.0"
let h = trpz.GetHeight()
printfn $"Trapezoid height is: {h}"
let dxR = trpz.GetLeftBaseRadianAngle()
printfn $"Trapezoid left base angle is: {dxR} Radians"
let dyR = trpz.GetRightBaseRadianAngle()
printfn $"Trapezoid right base angle is: {dyR} Radians"
let dxD = trpz.GetLeftBaseDegreeAngle()
printfn $"Trapezoid left base angle is: {dxD} Degrees"
let dyD = trpz.GetRightBaseDegreeAngle()
printfn $"Trapezoid left base angle is: {dyD} Degrees"
'The following class represents simple functionality of the trapezoid.
Class MathTrapezoidSample
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 Main()
Dim trpz As MathTrapezoidSample = New MathTrapezoidSample(20, 10, 8, 6)
Console.WriteLine("The trapezoid's bases are 20.0 and 10.0, the trapezoid's legs are 8.0 and 6.0")
Dim h As Double = trpz.GetHeight()
Console.WriteLine("Trapezoid height is: " + h.ToString())
Dim dxR As Double = trpz.GetLeftBaseRadianAngle()
Console.WriteLine("Trapezoid left base angle is: " + dxR.ToString() + " Radians")
Dim dyR As Double = trpz.GetRightBaseRadianAngle()
Console.WriteLine("Trapezoid right base angle is: " + dyR.ToString() + " Radians")
Dim dxD As Double = trpz.GetLeftBaseDegreeAngle()
Console.WriteLine("Trapezoid left base angle is: " + dxD.ToString() + " Degrees")
Dim dyD As Double = trpz.GetRightBaseDegreeAngle()
Console.WriteLine("Trapezoid left base angle is: " + dyD.ToString() + " Degrees")
End Sub
End Class
Remarks
Multiply the return value by 180/Math.PI to convert from radians to degrees.
This method calls into the underlying C runtime, and the exact result or valid input range may differ between different operating systems or architectures.