using?System;
using?System.Collections.Generic;
using?System.Text;

namespace?Geo2D
{
????public?static?class?m_Math
????{
????????//常數π
????????public?const?Double?Pi?=?3.1415926535;
????????//常數e
????????public?const?Double?E?=?2.7182818284;
????????//計算精度
????????public?const?Double?_precision?=?0.00001;

????????///?

????????///?牛頓迭代法求平方根
????????///?

????????///?被開方數
????????///?n的平方根
????????public?static?Double?sqrt（Double?n）
????????{
????????????double?result?=?0.0?delta?=?0.0;
????????????double?x?=?0.618?*?n;
????????????do
????????????{
????????????????result?=?0.5?*?（x?+?（n?/?x））;
????????????????delta?=?Math.Abs（x?-?result）;
????????????????x?=?result;
????????????}?while?（delta?>?m_Math._precision）;
????????????return?result;
????????}
????????///?

????????///?將角度轉化為對應的弧度
????????///?

????????///?角度值
????????///?radiand的角度值
????????public?static?Double?RadianToAngle（Double?radian）
????????{
????????????return?（180.0?*?radian）?/?m_Math.Pi;
????????}
????????///?

????????///?將弧度轉化為對應的角度
????????///?

????????///?
????????///?angle的弧度值
????????public?static?Double?AngleToRadian（Double?angle）
????????{
????????????return?（m_Math.Pi?*?angle）?/?180.0;
????????}
????}
????///?

????///?二維點
????///?

????public?class?Point2D
????{
????????public?Point2D（）?{?}
????????///?

????????///?二維點的坐標值
????????///?

????????///?x坐標值
????????///?y坐標值
????????public?Point2D（Double?xDouble?y）
????????{
????????????this.X?=?x;
????????????this.Y?=?y;
????????}

????????///?

????????///?X?coordinate?figure
????????///?

????????private?Double?_X;

????????///?

????????///?Y?coordinate?figure
????????///?

????????private?Double?_Y;

????????public?Double?X
????????{
????????????get
????????????{
????????????????return?this._X;
????????????}

????????????set
????????????{
????????????????this._X?=?value;
????????????}
????????}

????????public?Double?Y
????????{
????????????get
????????????{
????????????????return?this._Y;
????????????}

????????????set
????????????{
????????????????this._Y?=?value;
????????????}
????????}
????????///?

????????///?求本點到參數點的歐氏距離
????????///?

????????///?參數點
????????///?本點到參數點的歐氏距離
????????public?Double?GetDistanceTo（Point2D?p）
????????{
????????????Double?dx?=?this.X?-?p.X;
????????????Double?dy?=?this.Y?-?p.Y;
????????????return?Math.Sqrt（dx?*?dx?+?dy?*?dy）;
????????}
????????///?

????????///?生成以本點為起點?以參數點為終止點的二維向量
????????///?

????????///?參數點
????????///?
????????public?Vect