diff --git a/labs/inheritance/cp1/input.txt b/labs/inheritance/cp1/input.txt
new file mode 100644
index 0000000..a5164a6
--- /dev/null
+++ b/labs/inheritance/cp1/input.txt
@@ -0,0 +1,31 @@
+black       (1,0) (0.5,0.866) (1,1.732) (3,1.732) (3.5,0.866) (3,0) 
+blue        (0,0) (0,1) (1,1) (1,0) 
+brown       (2,0) (0,1) (3,3)
+cyan        (0,0) (0,2) (1,0)
+green       (0,0) (0,1) (1,0) 
+grey        (1,0) (1.5,0.866) (1,1.732) (2,1.732) (2.5,0.866) (2,0)
+magenta     (0,0) (1,1) (4,1) (3,0)
+olive       (0,0) (1,2) (6,3) (4,0)
+orange      (0,0) (0,3) (2,3) (2,0)
+pink        (1,0) (0,2) (4,2) (3,0)
+purple      (0,0) (0,2) (3,1)
+red         (0,0) (0.5,0.866) (1,0)
+teal        (1,0) (0,3) (1,4) (2,3)
+white       (2,0) (0,1) (3,4) (6,1) (4,0)
+yellow      (0,1) (2,2) (4,1) (2,0)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/labs/inheritance/cp2/output_simple.txt b/labs/inheritance/cp2/output_simple.txt
new file mode 100644
index 0000000..c4eda00
--- /dev/null
+++ b/labs/inheritance/cp2/output_simple.txt
@@ -0,0 +1,8 @@
+7 Polygon(s):  blue brown grey olive orange purple red
+3 Triangle(s):  brown purple red
+2 IsoscelesTriangle(s):  purple red
+1 EquilateralTriangle(s):  red
+3 Quadrilateral(s):  blue olive orange
+2 Rectangle(s):  blue orange
+1 Square(s):  blue
+3 Shape(s) with all equal sides:  blue grey red
diff --git a/labs/inheritance/cp2/simple.txt b/labs/inheritance/cp2/simple.txt
new file mode 100644
index 0000000..353859c
--- /dev/null
+++ b/labs/inheritance/cp2/simple.txt
@@ -0,0 +1,7 @@
+blue        (0,0) (0,1) (1,1) (1,0) 
+brown       (2,0) (0,1) (3,3)
+grey        (1,0) (1.5,0.866) (1,1.732) (2,1.732) (2.5,0.866) (2,0)
+olive       (0,0) (1,2) (6,3) (4,0)
+orange      (0,0) (0,3) (2,3) (2,0)
+purple      (0,0) (0,2) (3,1)
+red         (0,0) (0.5,0.866) (1,0)
diff --git a/labs/inheritance/cp2/simple_main.cpp b/labs/inheritance/cp2/simple_main.cpp
new file mode 100644
index 0000000..d3ebe2d
--- /dev/null
+++ b/labs/inheritance/cp2/simple_main.cpp
@@ -0,0 +1,168 @@
+#include <cassert>
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <vector>
+#include <cstdlib>
+#include <algorithm>
+
+#include "polygons.h"
+
+// helper function prototypes
+Polygon* CreatePolygon(const std::string &name, const std::vector<Point> &points);
+void OutputStats(const std::vector<Polygon*> &polygons, std::ofstream &ostr);
+
+// ------------------------------------------------------------------------------
+
+int main(int argc, char* argv[]) {
+
+  // command line arguments & opening files
+  if (argc != 3) { 
+    std::cerr << "Usage: " << argv[0] << " input.txt output.txt" << std::endl; 
+    exit(1);
+  }
+  std::ifstream istr(argv[1]);
+  if (!istr) {
+    std::cerr << "ERROR: could not open " << argv[1] << std::endl; 
+    exit(1);
+  }    
+  std::ofstream ostr(argv[2]);
+  if (!ostr) {
+    std::cerr << "ERROR: could not open " << argv[2] << std::endl; 
+    exit(1);
+  }    
+
+  // the master container of polygons
+  std::vector<Polygon*> polygons;
+
+  // read the input file one line at a time
+  std::string line;
+  while (getline(istr,line)) {
+    std::stringstream ss(line);
+    std::string name, token;
+    if (!(ss >> name)) continue;
+    std::vector<Point> points;
+    while (ss >> token) {
+      std::stringstream ss2(token);
+      char c;
+      double x,y;
+      ss2 >> c;
+      assert (c == '(');
+      ss2 >> x;
+      ss2 >> c;
+      assert (c == ',');
+      ss2 >> y;
+      ss2 >> c;
+      assert (c == ')');
+      points.push_back(Point(x,y));
+    }   
+    assert (points.size() >= 3);
+    Polygon* p = CreatePolygon(name,points);
+    // add the new polygon to the master container
+    polygons.push_back(p);
+  }
+
+  // write out the statistics
+  OutputStats(polygons,ostr);
+
+  // delete the dynamically allocated polygons
+  for (int i = 0; i < polygons.size(); i++) {
+    delete polygons[i];
+  }
+}
+
+// ------------------------------------------------------------------------------
+
+// This function determines the most specific type of shape that can
+// be created from the sequence of points.  It does this by process of
+// elimination.  Note that the order in which it attempts to create
+// the shapes is important.
+
+Polygon* CreatePolygon(const std::string &name, const std::vector<Point> &points) {
+  Polygon *answer = NULL;
+  try{
+    answer = new EquilateralTriangle(name,points);
+  } 
+  catch (int) { 
+    try {
+      answer= new IsoscelesTriangle(name,points);
+    }
+    catch (int) {
+      try {
+        answer= new Triangle(name,points);
+      }
+      catch (int) {
+        try {
+          answer= new Square(name,points);
+        }
+        catch (int) {
+          try {
+            answer= new Rectangle(name,points);
+          }
+          catch (int) {
+            try {
+              answer= new Quadrilateral(name,points);
+            }
+            catch (int) {
+              answer= new Polygon(name,points);
+            }
+          }
+	}
+      }
+    }
+  }
+  assert (answer != NULL);
+  return answer;
+}
+
+// ------------------------------------------------------------------------------
+
+// This function prints the output.  C++ macros are used to abbreviate
+// some repetitive code.  The function call-like macros are actually
+// replaced using substitution by the preprocessor before the code is
+// given to the compiler.  (You are not required to understand the
+// details of the macros.  You do not need to edit this code.)
+
+void OutputStats(const std::vector<Polygon*> &polygons, std::ofstream &ostr) {
+
+  // define and initialize variables
+# define InitializeCount(type) std::vector<std::string> all_##type
+  InitializeCount(Polygon);
+  InitializeCount(Triangle);
+  InitializeCount(IsoscelesTriangle);
+  InitializeCount(EquilateralTriangle);
+  InitializeCount(Quadrilateral);
+  InitializeCount(Rectangle);
+  InitializeCount(Square);  
+  std::vector<std::string> equal_sides;
+
+  // count & record the names of shapes in each category
+  for (std::vector<Polygon*>::const_iterator i = polygons.begin(); i!=polygons.end(); ++i) {
+#   define IncrementCount(type) if (dynamic_cast<type*> (*i)) all_##type.push_back((*i)->getName())
+    IncrementCount(Polygon);
+    IncrementCount(Triangle);
+    IncrementCount(IsoscelesTriangle);
+    IncrementCount(EquilateralTriangle);
+    IncrementCount(Quadrilateral);
+    IncrementCount(Rectangle);
+    IncrementCount(Square);
+    if ((*i)->HasAllEqualSides()) equal_sides.push_back((*i)->getName());
+  }    
+
+
+  // output data for each category, sorted alphabetically by the shape's name
+# define PrintVector(vecname) std::sort((vecname).begin(),(vecname).end()); \
+  for (unsigned int j = 0; j < (vecname).size(); j++) { ostr << " " << (vecname)[j]; } ostr << std::endl
+# define PrintCount(type) do { ostr << all_##type.size() << " " #type"(s): "; PrintVector(all_##type); } while (0)
+  PrintCount(Polygon);
+  PrintCount(Triangle);
+  PrintCount(IsoscelesTriangle);
+  PrintCount(EquilateralTriangle);
+  PrintCount(Quadrilateral);
+  PrintCount(Rectangle);
+  PrintCount(Square);
+  ostr << equal_sides.size() << " Shape(s) with all equal sides: ";
+  PrintVector(equal_sides);
+}
+
+// ------------------------------------------------------------------------------
diff --git a/labs/inheritance/cp2/utilities.h b/labs/inheritance/cp2/utilities.h
new file mode 100644
index 0000000..e0d1ec6
--- /dev/null
+++ b/labs/inheritance/cp2/utilities.h
@@ -0,0 +1,120 @@
+// =========================================
+//
+//  IMPORTANT NOTE: DO NOT EDIT THIS FILE
+//
+// =========================================
+
+#ifndef _UTILITIES_H_
+#define _UTILITIES_H_
+
+#include <iostream>
+#include <cmath>
+#include <cassert>
+
+// epsilon values used in comparing the edge lengths & angles between
+// edges note that these values are dependent on the precision of
+// the coordinates and the overall scale of the objects
+#define DISTANCE_EPSILON 0.0001
+#define ANGLE_EPSILON 0.1
+
+// -----------------------------------------------------------------
+
+// Stores a 2D coordinate
+class Point {
+public:
+  Point(double _x, double _y) : x(_x),y(_y) {}
+  double x;
+  double y;
+};
+
+// Stores a 2D vector, constructed from 2 Points
+class Vector {
+public:
+  Vector(const Point &a, const Point &b) { dx = b.x-a.x; dy = b.y-a.y; }
+  double Length() const { return sqrt(dx*dx+dy*dy); }
+  void Normalize() {
+    // make this a unit vector (length = 1)
+    double length = Length();
+    if (length < DISTANCE_EPSILON) throw std::string("LENGTH = 0");
+    assert (length > DISTANCE_EPSILON);
+    dx /= length;
+    dy /= length;
+  }
+  // representation
+  double dx;
+  double dy;
+};
+
+
+inline std::ostream& operator<< (std::ostream &ostr, const Vector &v) {
+  ostr << "<" << v.dx << "," << v.dy << ">";
+  return ostr;
+}
+
+
+// -----------------------------------------------------------------
+
+// calculate the length of an edge, the distance between 2 points
+inline double DistanceBetween(const Point &a, const Point &b) { 
+  Vector v(a,b);
+  return v.Length();
+}
+
+// Calculate the angle at vertex b in degrees, that is, the angle
+// between edges ab and bc.  This will return a positive number
+// measured as the clockwise rotation in the xy plane from point c to
+// point a (rotating around point b).
+inline double Angle(const Point &a, const Point &b, const Point &c) {
+  // make unit vector along each of the edges
+  Vector ba(b,a);  ba.Normalize();
+  Vector bc(b,c);  bc.Normalize();
+  // calculate the angle in radians
+  double dot_product = ba.dx * bc.dx + ba.dy * bc.dy;
+
+  if (dot_product < -1 || dot_product > 1) throw std::string("DOT PRODUCT RANGE");
+
+  assert (dot_product >= -1 && dot_product <= 1);
+  float perpDot = ba.dx * bc.dy - ba.dy * bc.dx;
+  // using atan2 to ensure than we get a signed answer.
+  double angle_in_radians = atan2(perpDot, dot_product);
+  // convert to degrees
+  double answer = angle_in_radians * 180.0 / M_PI;
+  if (answer < 0) {
+    answer += 360;
+  }
+  assert (answer >= 0 && answer <= 360);
+  return answer;
+}
+
+// returns true if these two vectors are parallel
+inline bool Parallel(const Vector &a, const Vector &b) {
+  Vector a2 = a; a2.Normalize();
+  Vector b2 = b; b2.Normalize();
+  double dot_product = a2.dx * b2.dx + a2.dy * b2.dy;
+  // parallel vectors have dot product == 1
+  if (fabs(dot_product) > 1-DISTANCE_EPSILON) return true;
+  return false;
+}
+
+
+// -----------------------------------------------------------------
+// simple functions for angles & sides
+
+inline bool EqualSides(double a, double b) {
+  return (fabs(a-b) < DISTANCE_EPSILON);
+}
+
+inline bool EqualAngles(double a, double b) {
+  assert (a >= 0.0 && a < 360.0);
+  assert (b >= 0.0 && b < 360.0);
+  return (fabs(a-b) < ANGLE_EPSILON);
+}
+
+inline bool RightAngle(double a) {
+  assert (a >= 0.0 && a < 360.0);
+  return (fabs(a-90.0)  < ANGLE_EPSILON);
+}
+
+// -----------------------------------------------------------------
+
+#endif
diff --git a/labs/inheritance/cp3/main.cpp b/labs/inheritance/cp3/main.cpp
new file mode 100644
index 0000000..9c7028e
--- /dev/null
+++ b/labs/inheritance/cp3/main.cpp
@@ -0,0 +1,223 @@
+#include <cassert>
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <vector>
+#include <cstdlib>
+#include <algorithm>
+
+#include "polygons.h"
+
+// helper function prototypes
+Polygon* CreatePolygon(const std::string &name, const std::vector<Point> &points);
+void OutputStats(const std::vector<Polygon*> &polygons, std::ofstream &ostr);
+
+// ------------------------------------------------------------------------------
+
+int main(int argc, char* argv[]) {
+
+  // command line arguments & opening files
+  if (argc != 3) { 
+    std::cerr << "Usage: " << argv[0] << " input.txt output.txt" << std::endl; 
+    exit(1);
+  }
+  std::ifstream istr(argv[1]);
+  if (!istr) {
+    std::cerr << "ERROR: could not open " << argv[1] << std::endl; 
+    exit(1);
+  }    
+  std::ofstream ostr(argv[2]);
+  if (!ostr) {
+    std::cerr << "ERROR: could not open " << argv[2] << std::endl; 
+    exit(1);
+  }    
+
+  // the master container of polygons
+  std::vector<Polygon*> polygons;
+
+  // read the input file one line at a time
+  std::string line;
+  while (getline(istr,line)) {
+    std::stringstream ss(line);
+    std::string name, token;
+    if (!(ss >> name)) continue;
+    std::vector<Point> points;
+    while (ss >> token) {
+      std::stringstream ss2(token);
+      char c;
+      double x,y;
+      ss2 >> c;
+      assert (c == '(');
+      ss2 >> x;
+      ss2 >> c;
+      assert (c == ',');
+      ss2 >> y;
+      ss2 >> c;
+      assert (c == ')');
+      points.push_back(Point(x,y));
+    }   
+    assert (points.size() >= 3);
+    Polygon* p = CreatePolygon(name,points);
+    // add the new polygon to the master container
+    polygons.push_back(p);
+  }
+
+  // write out the statistics
+  OutputStats(polygons,ostr);
+
+  // delete the dynamically allocated polygons
+  for (int i = 0; i < polygons.size(); i++) {
+    delete polygons[i];
+  }
+}
+
+// ------------------------------------------------------------------------------
+
+// This function determines the most specific type of shape that can
+// be created from the sequence of points.  It does this by process of
+// elimination.  Note that the order in which it attempts to create
+// the shapes is important.
+
+Polygon* CreatePolygon(const std::string &name, const std::vector<Point> &points) {
+  Polygon *answer = NULL;
+  try{
+    answer = new EquilateralTriangle(name,points);
+  } 
+  catch (int) { 
+    try {
+      answer= new IsoscelesRightTriangle(name,points);
+    }
+    catch (int) {
+      try {
+        answer= new RightTriangle(name,points);
+      }
+      catch (int) {
+        try {
+          answer= new IsoscelesTriangle(name,points);
+        }
+        catch (int) {
+          try {
+            answer= new Triangle(name,points);
+          }
+          catch (int) {
+            try {
+              answer= new Square(name,points);
+            }
+            catch (int) {
+              try {
+                answer= new Rectangle(name,points);
+              }
+              catch (int) {
+                try {
+                  answer= new Rhombus(name,points);
+                }
+                catch (int) {
+                  try {
+                    answer= new Parallelogram(name,points);
+                  }
+                  catch (int) {
+                    try {
+                      answer= new Kite(name,points);
+                    }
+                    catch (int) {
+                      try {
+                        answer= new Trapezoid(name,points);
+                      }
+                      catch (int) {
+                        try {
+                          answer= new Quadrilateral(name,points);
+                        }
+                        catch (int) {
+                          answer= new Polygon(name,points);
+                        }
+                      }
+		    }
+		  }
+		}
+	      }
+	    }
+	  }
+	}
+      }
+    }
+  }
+  assert (answer != NULL);
+  return answer;
+}
+
+// ------------------------------------------------------------------------------
+
+// This function prints the output.  C++ macros are used to abbreviate
+// some repetitive code.  The function call-like macros are actually
+// replaced using substitution by the preprocessor before the code is
+// given to the compiler.  (You are not required to understand the
+// details of the macros.  You do not need to edit this code.)
+
+void OutputStats(const std::vector<Polygon*> &polygons, std::ofstream &ostr) {
+
+  // define and initialize variables
+# define InitializeCount(type) std::vector<std::string> all_##type
+  InitializeCount(Polygon);
+  InitializeCount(Triangle);
+  InitializeCount(IsoscelesTriangle);
+  InitializeCount(RightTriangle);
+  InitializeCount(IsoscelesRightTriangle);
+  InitializeCount(EquilateralTriangle);
+  InitializeCount(Quadrilateral);
+  InitializeCount(Trapezoid);
+  InitializeCount(Kite);
+  InitializeCount(Parallelogram);
+  InitializeCount(Rhombus);
+  InitializeCount(Rectangle);
+  InitializeCount(Square);  
+  std::vector<std::string> equal_sides;
+  std::vector<std::string> equal_angles;
+  std::vector<std::string> right_angle;
+
+  // count & record the names of shapes in each category
+  for (std::vector<Polygon*>::const_iterator i = polygons.begin(); i!=polygons.end(); ++i) {
+#   define IncrementCount(type) if (dynamic_cast<type*> (*i)) all_##type.push_back((*i)->getName())
+    IncrementCount(Polygon);
+    IncrementCount(Triangle);
+    IncrementCount(IsoscelesTriangle);
+    IncrementCount(RightTriangle);
+    IncrementCount(IsoscelesRightTriangle);
+    IncrementCount(EquilateralTriangle);
+    IncrementCount(Quadrilateral);
+    IncrementCount(Trapezoid);
+    IncrementCount(Kite);
+    IncrementCount(Parallelogram);
+    IncrementCount(Rhombus);
+    IncrementCount(Rectangle);
+    IncrementCount(Square);
+    if ((*i)->HasAllEqualSides()) equal_sides.push_back((*i)->getName());
+    if ((*i)->HasAllEqualAngles()) equal_angles.push_back((*i)->getName());
+    if ((*i)->HasARightAngle()) right_angle.push_back((*i)->getName());
+  }    
+
+  // output data for each category, sorted alphabetically by the shape's name
+# define PrintVector(vecname) std::sort((vecname).begin(),(vecname).end()); \
+  for (unsigned int j = 0; j < (vecname).size(); j++) { ostr << " " << (vecname)[j]; } ostr << std::endl
+# define PrintCount(type) do { ostr << all_##type.size() << " " #type"(s): "; PrintVector(all_##type); } while (0)
+  PrintCount(Polygon);
+  PrintCount(Triangle);
+  PrintCount(IsoscelesTriangle);
+  PrintCount(RightTriangle);
+  PrintCount(IsoscelesRightTriangle);
+  PrintCount(EquilateralTriangle);
+  PrintCount(Quadrilateral);
+  PrintCount(Trapezoid);
+  PrintCount(Kite);
+  PrintCount(Parallelogram);
+  PrintCount(Rhombus);
+  PrintCount(Rectangle);
+  PrintCount(Square);
+  ostr << equal_sides.size() << " Shape(s) with all equal sides: ";
+  PrintVector(equal_sides);
+  ostr << equal_angles.size() << " Shape(s) with all equal angles: ";
+  PrintVector(equal_angles);
+  ostr << right_angle.size() << " Shape(s) with a right angle: ";
+  PrintVector(right_angle);
+}
+
+// ------------------------------------------------------------------------------
diff --git a/labs/inheritance/cp3/quads.txt b/labs/inheritance/cp3/quads.txt
new file mode 100644
index 0000000..2bdf20c
--- /dev/null
+++ b/labs/inheritance/cp3/quads.txt
@@ -0,0 +1,9 @@
+blue        (0,0) (0,1) (1,1) (1,0) 
+orange      (0,0) (0,3) (2,3) (2,0)
+yellow      (0,1) (2,2) (4,1) (2,0)
+magenta     (0,0) (1,1) (4,1) (3,0)
+pink        (1,0) (0,2) (4,2) (3,0)
+teal        (1,0) (0,3) (1,4) (2,3)
+olive       (0,0) (1,2) (6,3) (4,0)
+
+
diff --git a/labs/inheritance/cp3/triangles.txt b/labs/inheritance/cp3/triangles.txt
new file mode 100644
index 0000000..b623368
--- /dev/null
+++ b/labs/inheritance/cp3/triangles.txt
@@ -0,0 +1,9 @@
+red         (0,0) (0.5,0.866) (1,0) 
+green       (0,0) (0,1) (1,0) 
+cyan        (0,0) (0,2) (1,0) 
+purple      (0,0) (0,2) (3,1) 
+brown       (2,0) (0,1) (3,3)
+
+
+
+
diff --git a/labs/inheritance/images/multiple_inheritance.png b/labs/inheritance/images/multiple_inheritance.png
new file mode 100644
index 0000000..3212bbb
Binary files /dev/null and b/labs/inheritance/images/multiple_inheritance.png differ
diff --git a/labs/inheritance/images/single_inheritance.png b/labs/inheritance/images/single_inheritance.png
new file mode 100644
index 0000000..9ab5261
Binary files /dev/null and b/labs/inheritance/images/single_inheritance.png differ