diff --git a/Mathe/Classes.cpp b/Mathe/Classes.cpp
new file mode 100644
index 0000000..5f62639
--- /dev/null
+++ b/Mathe/Classes.cpp
@@ -0,0 +1,92 @@
+#include<iostream>
+#include<string>
+#include<sstream>
+#include<math.h>
+
+class Point
+{
+	public:
+		double X, Y;
+		
+		void setX(double x)
+		{
+			X = x;
+		}
+		
+		void setY(double y)
+		{
+			Y = y;
+		}
+		
+		Point(double x = 0, double y = 0)
+		{
+			X = x;
+			Y = y;
+		}
+		
+		void print()
+		{
+			std::cout << "(" << X << "," << Y << ")";
+		}
+};
+
+class Line
+{
+	public:
+		Point P, Q;
+		double b, m;
+		
+		void setPoint(bool p, Point point)
+		{
+			if(p==0)
+			{
+				Q.setX(point.X);
+				Q.setY(point.Y);
+			}
+			else
+			{
+				P.setX(point.X);
+				P.setY(point.Y);
+			}
+		}
+		
+		void distance()
+		{
+			std::cout << sqrt((P.X-Q.X)*(P.X-Q.X)+(P.Y-Q.Y)*(P.Y-Q.Y));
+		}
+		
+		void gradient()
+		{
+			m = (P.Y-Q.Y)/(P.X-Q.X);
+		}
+		
+		void nullPointX()
+		{
+			b = (-P.X)*(P.Y-Q.Y)/(P.X-Q.X)+(P.Y);
+			std::cout << b;
+		}
+		
+		void nullPointY()
+		{
+			std::cout << (P.X)*(P.Y-Q.Y)/(P.X-Q.X)/((P.Y-Q.Y)/(P.X-Q.X));
+		}
+		
+		void print()
+		{
+			gradient();
+			
+			std::cout << m <<"*x + ";
+			
+			nullPointX();
+		}
+};
+
+int main()
+{
+	Point P(3,5), Q(5,3);
+	Line g;
+	g.setPoint(0, Q);
+	g.setPoint(1, P);
+	g.print();
+	getchar();
+}
diff --git a/Schleifen.cpp b/Schleifen.cpp
new file mode 100644
index 0000000..a803f67
--- /dev/null
+++ b/Schleifen.cpp
@@ -0,0 +1,92 @@
+#include<iostream>
+#include<string>
+#include<sstream>
+
+int main()
+{
+	long long depth;
+	std::string input;
+	
+	std::cout << "Geben sie die Tiefe ein: ";
+	getline(std::cin, input);
+	std::stringstream(input) >> depth;
+	
+	if(depth<2)
+	{
+		std::cout << "ERROR: Zahl muss größer als 1 sein.";
+		getchar();
+		return(1);
+	}
+	
+	for(long long idx = 0;  idx<depth*depth;  idx++)
+	{
+		if(idx%depth==0) std::cout << "\n";
+		std::cout << "*";
+	}
+	
+	std::cout << "\n";
+	
+	for(long long idx = 0;  idx<depth;  idx++)
+	{
+		std::cout << "\n";
+		
+		for(long long idx2 = 0;  idx2<idx;  idx2++)
+		{
+			std::cout << " ";
+		}
+		
+		for(long long idx2 = 0;  idx2<depth*2-1-2*idx;  idx2++)
+		{
+			std::cout << "*";
+		}
+	}
+	
+	std::cout << "\n\n";
+	
+	for(long long idx = 0;  idx<depth-1;  idx++)
+	{	
+		for(long long idx2 = 0;  idx2<depth-idx-1;  idx2++)
+		{
+			std::cout << " ";
+		}
+		
+		std::cout << "*";
+		
+		for(long long idx2 = 0;  idx2<2*idx-1;  idx2++)
+		{
+			std::cout << " ";
+		}
+		
+		if(idx>0) std::cout << "*";
+		
+		std::cout << "\n";
+	}
+	
+	for(long long idx = 0;  idx<2*depth-1;  idx++)
+	{
+		std::cout << "*";
+	}
+	
+	for(long long idx = 0;  idx<depth-2;  idx++)
+	{
+		std::cout << "\n*";
+		
+		for(long long idx2 = 0;  idx2<2*depth-3;  idx2++)
+		{
+			std::cout << " ";
+		}
+		
+		std::cout << "*";
+	}
+	
+	std::cout << "\n";
+	
+	for(long long idx = 0;  idx<2*depth-1;  idx++)
+	{
+		std::cout << "*";
+	}
+	
+	std::cout << "\n\n\n\nProgrammende!";
+	getchar();
+	return(0);
+}
diff --git a/Tage seit.cpp b/Tage seit.cpp
new file mode 100644
index 0000000..55c076c
--- /dev/null
+++ b/Tage seit.cpp	
@@ -0,0 +1,65 @@
+#include<iostream>
+#include<string>
+#include<sstream>
+int main()
+{
+	std::string stringInput;
+	unsigned long long day, month, year;
+	short daysInMonth[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30};
+	
+	std::cout << "Gib den Tag des Monats ein: ";
+	getline(std::cin, stringInput);
+	std::stringstream(stringInput) >> day;
+	
+	if(day>31 || day<1)
+	{
+		std::cout << "ERROR: Der eingegebene Tag existiert nicht.";
+		return(1);
+	}
+	
+	std::cout << "Gib den Monat ein: ";
+	getline(std::cin, stringInput);
+	std::stringstream(stringInput) >> month;
+	
+	if(month>12 || month<1)
+	{
+		std::cout << "ERROR: Der eingegebene Monat existiert nicht.";
+		return(1);
+	}
+	
+	if(day>daysInMonth[month] && month!=2 || month==2 && day>29)
+	{
+		std::cout << "ERROR: Es wurden zuviele Tage f\x81r diesen Monat eingegeben.";
+		return(1);
+	}
+	
+	if(day==29 && month==2) daysInMonth[1]++;
+	
+	std::cout << "Gib das Jahr ein: ";
+	getline(std::cin, stringInput);
+	std::stringstream(stringInput) >> year;
+	
+	if(year<0)
+	{
+		std::cout << "ERROR: Der 1. Januar 0 liegt in der Zukunft.";
+		return(1);
+	}
+	
+	if(day==29 && month == 2 && (year%4!=0 || year%100==0 && year%400!=0))
+	{
+		std::cout << "ERROR: Die bereits erfolgten Eingaben benötigen ein Schaltjahr.";
+		return(1);
+	}
+	
+	std::cout << "\nVom 1. Januar 0 bis zum " << day << "." << month << "." << year;
+	
+	for(short idx = 0; idx<month-1; idx++)
+	{
+		day += daysInMonth[idx];
+	}
+	
+	std::cout << " sind " << year*365+year/4-year/100+year/400+day-1 <<" Tage vergangen.";
+	
+	getchar();
+	return(0);
+}
diff --git a/weekday.cpp b/weekday.cpp
new file mode 100644
index 0000000..0118820
--- /dev/null
+++ b/weekday.cpp
@@ -0,0 +1,93 @@
+#include<iostream>
+#include<string>
+#include<sstream>
+#include<conio.h>
+
+int main()
+{
+	std::string input;
+	short day, month, daysInMonth[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, weekday, year;
+	
+	std::cout << "Gib das Tagesdatum ein: ";
+	getline(std::cin, input);
+	std::stringstream(input) >> day;
+	
+	if(day==0 || day>31)
+	{
+		std::cout << "\nERROR: Das eingegebene Tagesdatum existiert nicht.";
+		getch();
+		return(1);
+	}
+	
+	std::cout << "Gib den Monat ein: ";
+	getline(std::cin, input);
+	std::stringstream(input) >> month;
+	
+	if(daysInMonth[month-1]<day)
+	{
+		std::cout << "\nERROR: Der eingegebene Monat hat keine " << day << " Tage.";
+		getch();
+		return(1);
+	}
+	
+	if(month>12 || month==0)
+	{
+		std::cout << "\nERROR: Der eingegebene Tag existiert nicht.";
+		getch();
+		return(1);
+	}
+	
+	std::cout << "Gib das jahr ein: ";
+	getline(std::cin, input);
+	std::stringstream(input) >> year;
+	
+	if(year>10000 || year<0)
+	{
+		std::cout << "\nERROR: Im eingegeben Jahr lässt sich der Wochentag nicht ermitteln.";
+		getch();
+		return(1);
+	}
+	
+	if(day==29 && month==2 && (year%4!=0 || year%100==0))
+	{
+		std::cout << "\nERROR: Die Eingaben ben\x94tigen ein Schaltjahr.";
+		getch();
+		return(1);
+	}
+	
+	std::cout << "\nDer " << day << "." << month << "." << year << " war ein ";
+	
+	if(month==1 || month==2) year -=1;
+	
+	switch (month)
+	{
+		case 1:		month = 0;		break;
+		case 8:		month = 1;		break;
+		case 2:
+		case 6:		month = 3;		break;
+		case 9:
+		case 12:	month = 4;		break;
+		case 4:
+		case 7:		month = 5;		break;
+		case 10:	month = 6;		break;
+		default:	month = 2;		break;
+	}
+	
+	weekday = (day+month+(year%100)+(year%100/4)+year/400-2*(year/100))%7;
+	
+	while(weekday<0) weekday += 7;
+	
+	switch(weekday)
+	{
+		case 0:	std::cout << "Sonntag";		break;
+		case 1:	std::cout << "Montag";		break;
+		case 2:	std::cout << "Dienstag";	break;
+		case 3:	std::cout << "Mittwoch";	break;
+		case 4:	std::cout << "Donnerstag";	break;
+		case 5:	std::cout << "Freitag";		break;
+		case 6:	std::cout << "Samstag";		break;
+	}
+	
+	getch();
+	return(0);
+}