System.Math 类

System.Math 类例子

下面的示例使用 Math 类中的几个数学函数和三角函数来计算一个梯形的几个内角。

/// 

	/// The following class represents simple functionality of the trapezoid.
	/// 
	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");
		}
	}

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