Question

考虑到班级：

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上课：

public class Point3D
{

    public double X;
    public double Y;
    public double Z;

    public Point3D(double x, double y, double z)
    {
        X = x;
        Y = y;
        Z = z;
    }

    public double DistanceTo(Point3D to)
    {
        double dX = Math.Abs(to.X - X);
        double dY = Math.Abs(to.Y - Y);
        double dZ = Math.Abs(to.Z - Z);
        return Math.Sqrt(dX * dX + dY * dY + dZ * dZ);
    }

}

我想计算通过public class Segment { public Point3D From; public Point3D To; public double? Radius; public Segment(Point3D from, Point3D to, double? radius) { From = from; To = to; Radius = radius; } public double Length { get { double straightLength = From.DistanceTo(To); if (Radius == null) return straightLength; if (Radius < straightLength/ 2d) throw new Exception(); // Compute the arcuate segment length } } }和Radius 3D点的弧的长度（From}。

欢迎提供一些帮助！

Answer 1

根据http://mathworld.wolfram.com/IsoscelesTriangle.html

straightLength / 2 = Radius * sin( 1/2 * angle)

因此：

angle = 2 * arcsin( straightLength / 2 / Radius)

和

arcLength = Radius * angle;

Answer 2

还有一个参考： from math.stackexchange

S =弧的长度= r * theta，其中r =半径和Cos（θ）=（2个矢量的点积）/（这些矢量的模数的乘积）

计算弧形段长度的公式

2 个答案: