diff --git a/week_6.ipynb b/week_6.ipynb
new file mode 100644
index 0000000..6499225
--- /dev/null
+++ b/week_6.ipynb
@@ -0,0 +1,461 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "sharp-luxembourg",
+   "metadata": {},
+   "source": [
+    "* Create a class named Triangle and Rectangle.\n",
+    "    * Create a subclass named Square inherited from Rectangle.\n",
+    "    * Create a subclass named Cube inherited from Square.\n",
+    "    * Create a subclass named Pyramid multiple inherited both from Triangle and Square.\n",
+    "    \n",
+    "\n",
+    "* Two dimensional classes (Triangle, Rectangle and Square) should have:\n",
+    "    * its dimensions as attributes.(can be inherited from a superclass)\n",
+    "    * methods which calculate its area and perimeter separately. \n",
+    "    \n",
+    "\n",
+    "* Three dimensional classes (Cube and Pyramid) should have:\n",
+    "    * its dimensions as attributes which are inherited from a superclass\n",
+    "    * its extra dimensions if there is. (hint: maybe for Pyramid)\n",
+    "    * methods which calculate its volume and surface area separately. (surface area is optional, you may not do this)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 116,
+   "id": "surprised-lemon",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Triangle:\n",
+    "    def __init__(self, three_sides):\n",
+    "        self.three_sides=three_sides\n",
+    "      \n",
+    "    @property\n",
+    "    def perimeter(self):\n",
+    "        return sum(self.three_sides)    \n",
+    "    \n",
+    "    @property    \n",
+    "    def area(self):\n",
+    "        u = self.perimeter/2\n",
+    "        a,b,c = [i for i in self.three_sides]\n",
+    "        return (u*(u-a)*(u-b)*(u-c))**0.5\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Perimeter\\t:\\t{self.perimeter} cm\n",
+    "Area\\t\\t:\\t{round(self.area,1)} cm2\n",
+    "\"\"\"\n",
+    "\n",
+    "     \n",
+    "class Rectangle:   \n",
+    "    def __init__(self, two_sides):\n",
+    "        self.two_sides=two_sides\n",
+    "    \n",
+    "    @property\n",
+    "    def perimeter(self):\n",
+    "        return sum(self.two_sides)*2 \n",
+    "    \n",
+    "    @property    \n",
+    "    def area(self):\n",
+    "        a,b = [i for i in self.two_sides]\n",
+    "        return a*b\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Perimeter\\t:\\t{self.perimeter} cm\n",
+    "Area\\t\\t:\\t{self.area} cm2\n",
+    "\"\"\"\n",
+    "    \n",
+    "class Square(Rectangle):\n",
+    "    def __init__(self,two_sides):\n",
+    "        super().__init__(two_sides)\n",
+    "        \n",
+    "    @property    \n",
+    "    def perimeter(self):\n",
+    "        a = self.two_sides[0]\n",
+    "        return 4 * a  \n",
+    "    \n",
+    "    @property    \n",
+    "    def area(self):\n",
+    "        a = self.two_sides[0]\n",
+    "        return a**2  \n",
+    "\n",
+    "class Cube(Square):\n",
+    "    def __init__(self,two_sides):\n",
+    "        super().__init__(two_sides)    \n",
+    "        \n",
+    "    @property    \n",
+    "    def area(self):\n",
+    "        a = self.two_sides[0]\n",
+    "        return 6 * a**2\n",
+    "    \n",
+    "    @property    \n",
+    "    def volume(self):\n",
+    "        a = self.two_sides[0]\n",
+    "        return a**3\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Area\\t:\\t{self.area} cm2\n",
+    "Volume\\t:\\t{self.volume} cm3\n",
+    "\"\"\"\n",
+    "    \n",
+    "class Pyramid(Triangle, Square):\n",
+    "    def __init__(self, two_sides, height, three_sides=None):\n",
+    "        Triangle.__init__(self,three_sides)\n",
+    "        Square.__init__(self,two_sides)\n",
+    "        self.height = height\n",
+    "      \n",
+    "    @property    \n",
+    "    def area(self):\n",
+    "        a = self.two_sides[0]\n",
+    "        h = self.height\n",
+    "        return a**2 + a*(a**2+4*h**2)**0.5\n",
+    "    \n",
+    "    @property    \n",
+    "    def volume(self):\n",
+    "        a = self.two_sides[0]\n",
+    "        h = self.height\n",
+    "        return 1/3 * a**2 * h\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Area\\t:\\t{round(self.area,1)} cm2\n",
+    "Volume\\t:\\t{self.volume} cm3\n",
+    "\"\"\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 117,
+   "id": "instrumental-place",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#This Part is extra\n",
+    "from math import pi\n",
+    "\n",
+    "class Circle:\n",
+    "    def __init__(self, radius):\n",
+    "        self.radius = radius\n",
+    "        \n",
+    "    @property\n",
+    "    def perimeter(self):\n",
+    "        r = self.radius\n",
+    "        return 2*pi*r \n",
+    "    \n",
+    "    @property\n",
+    "    def area(self):  \n",
+    "        return (self.perimeter**2)/(4*pi)\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Perimeter\\t:\\t{round(self.perimeter,1)} cm\n",
+    "Area\\t\\t:\\t{round(self.area,1)} cm2\"\"\"\n",
+    "    \n",
+    "\n",
+    "class Sphere(Circle):\n",
+    "    def __init__(self,radius):\n",
+    "        super().__init__(radius) \n",
+    "        self.radius=radius\n",
+    "    \n",
+    "    @property\n",
+    "    def area(self):  \n",
+    "        r = self.radius\n",
+    "        return 4*pi*r**2\n",
+    "    \n",
+    "    @property    \n",
+    "    def volume(self):\n",
+    "        r = self.radius\n",
+    "        return 1/3 * pi * r**3\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Area\\t:\\t{round(self.area,1)} cm2\n",
+    "Volume\\t:\\t{round(self.volume,1)} cm3\n",
+    "\"\"\"\n",
+    "    \n",
+    "class Cylinder(Circle):\n",
+    "    def __init__(self,radius, height):\n",
+    "        super().__init__(radius) \n",
+    "        self.radius=radius\n",
+    "        self.height=height\n",
+    "    \n",
+    "    @property\n",
+    "    def area(self):  \n",
+    "        r = self.radius\n",
+    "        h = self.height\n",
+    "        return 2*pi*r*(h + r)\n",
+    "    \n",
+    "    @property    \n",
+    "    def volume(self):\n",
+    "        r = self.radius\n",
+    "        h = self.height\n",
+    "        return pi*h*r**2\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Area\\t:\\t{round(self.area,1)} cm2\n",
+    "Volume\\t:\\t{round(self.volume,1)} cm3\n",
+    "\"\"\"\n",
+    "    \n",
+    "class Cone(Circle):\n",
+    "    def __init__(self,radius, height):\n",
+    "        super().__init__(radius) \n",
+    "        self.radius=radius\n",
+    "        self.height=height\n",
+    "    \n",
+    "    @property\n",
+    "    def area(self):  \n",
+    "        r = self.radius\n",
+    "        h = self.height\n",
+    "        return pi*r*(r + (r**2 + h**2)**0.5)\n",
+    "    \n",
+    "    @property    \n",
+    "    def volume(self):\n",
+    "        r = self.radius\n",
+    "        h = self.height\n",
+    "        return 1/3*pi*h*r**2\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return f\"\"\"Area\\t:\\t{round(self.area,1)} cm2\n",
+    "Volume\\t:\\t{round(self.volume,1)} cm3\n",
+    "\"\"\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 118,
+   "id": "disturbed-buddy",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Perimeter\t:\t12 cm\n",
+      "Area\t\t:\t6.0 cm2\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "triangle_sides = [3,4,5]\n",
+    "obj1 = Triangle(triangle_sides)\n",
+    "\n",
+    "print(obj1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 119,
+   "id": "aboriginal-leonard",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Perimeter\t:\t14 cm\n",
+      "Area\t\t:\t12 cm2\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "rectangle_sides = [3,4]\n",
+    "obj2 = Rectangle(rectangle_sides)\n",
+    "\n",
+    "print(obj2)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 120,
+   "id": "lovely-nigeria",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Perimeter\t:\t20 cm\n",
+      "Area\t\t:\t25 cm2\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "square_side = [5]\n",
+    "obj3 = Square(square_side)\n",
+    "\n",
+    "print(obj3)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 121,
+   "id": "therapeutic-placement",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Area\t:\t24 cm2\n",
+      "Volume\t:\t8 cm3\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "cube_side = [2]\n",
+    "obj4 = Cube(cube_side)\n",
+    "\n",
+    "print(obj4)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 122,
+   "id": "incident-storm",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Area\t:\t34.6 cm2\n",
+      "Volume\t:\t12.0 cm3\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "pyramid_square_base_side = [3]\n",
+    "pyramid_height = 4\n",
+    "obj5 = Pyramid(pyramid_square_base_side, pyramid_height)\n",
+    "\n",
+    "print(obj5)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 123,
+   "id": "juvenile-leeds",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Perimeter\t:\t12.6 cm\n",
+      "Area\t\t:\t12.6 cm2\n"
+     ]
+    }
+   ],
+   "source": [
+    "circle_radius = 2\n",
+    "obj6 = Circle(circle_radius)\n",
+    "\n",
+    "print(obj6)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 124,
+   "id": "moving-jewelry",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Area\t:\t50.3 cm2\n",
+      "Volume\t:\t8.4 cm3\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "sphere_radius = 2\n",
+    "obj7 = Sphere(sphere_radius)\n",
+    "\n",
+    "print(obj7)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 125,
+   "id": "balanced-adoption",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Area\t:\t75.4 cm2\n",
+      "Volume\t:\t50.3 cm3\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "cylinder_radius = 2\n",
+    "cylinder_height = 4\n",
+    "obj8 = Cylinder(cylinder_radius, cylinder_height)\n",
+    "\n",
+    "print(obj8)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 126,
+   "id": "average-credits",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Area\t:\t40.7 cm2\n",
+      "Volume\t:\t16.8 cm3\n",
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "cone_radius = 2\n",
+    "cone_height = 4\n",
+    "obj9 = Cone(cone_radius, cone_height)\n",
+    "\n",
+    "print(obj9)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "useful-cheese",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.5"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}