diff --git a/Figure.c b/Figure.c
index 425b42c..6d5f37e 100644
--- a/Figure.c
+++ b/Figure.c
@@ -3,15 +3,15 @@
 /* considered to be protected */
 void Figure_constructor (Figure *this)
 {
-  // nothin here
+  // nothing here
 }
 
 void Figure_destructor (Figure *this)
 {
-  // nothin here
+  // nothing here
 }
 
 void Figure_copy (struct Figure *dest, const struct Figure *src)
 {
-  // nothin here
+  // nothing here
 }
diff --git a/Polygon.c b/Polygon.c
index ca00ac1..de04a6b 100644
--- a/Polygon.c
+++ b/Polygon.c
@@ -1,5 +1,28 @@
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
 #include "Polygon.h"
 
+/* considered to be protected */
+void Polygon_constructor (Polygon *this, const struct point *points, int npoints)
+{
+  Figure_constructor ((Figure *) this);
+  this->npoints = npoints;
+  this->points = strdup (points, npoints * sizeof (struct point));
+}
+
+void Polygon_destructor (Polygon *this)
+{
+  free (this->points);
+}
+
+void Polygon_copy (Polygon *dest, const Polygon *src)
+{
+  dest->npoints = src->npoints;
+  dest->points = strdup (src->points, src->npoints * sizeof (struct point));
+}
+
 /* private */
 static const char* __Polygon_type ()
 {
@@ -8,47 +31,74 @@ static const char* __Polygon_type ()
 
 static Polygon* __Polygon_clone (const Polygon *this)
 {
-
+  Polygon *poly = malloc (sizeof (Polygon));
+  memset (poly, 0, sizeof (
+  Polygon_copy (poly, this);
+  return poly;
 }
 
 static void __Polygon_destroy (Polygon *this)
 {
-
+  Polygon_destructor (this);
+  g_free (this);
 }
 
 static void __Polygon_draw (const Polygon *this)
 {
+  int i = 0;
 
+  for (i = 0; i < this->npoints; i++)
+    {
+      printf ("{%f;%f}, ", this->points[i].x, this->points[i].y);
+    }
+  printf ("{%f;%f}, ", this->points[0].x, this->points[0].y);
 }
 
 static double __Polygon_area (const Polygon *this)
 {
+  double s = 0.0, x, y; 
+  int i = 0;
 
+  for (i = 0; i < this->npoints; i++)
+    {
+      s += this->points[i].x * this->points[(i + 1) % this->npoints].y -
+           this->points[(i + 1) % this->npoints].x * this->points[i].y;
+    }
+
+  return s * 0.5;
+  // Trapezium rule for convex and non-convex polygons
+  // S=abs(сумма{(x[i+1]-x[i])*(y[i+1]+y[i])/2})
 }
 
 static double __Polygon_max_diag (const Polygon *this)
 {
+  double diag = 0.0,
+         tmp = 0.0,
+         tmp1 = 0.0,
+         tmp2 = 0.0;
+  int i = 0, j = 0;
 
+  for (i = 0; i < this->npoints - 2; i++)
+    {
+      for (j = i + 2; j < this->npoints; j++)
+        {
+          tmp1 = (this->points[i].x - this->points[j].x);
+          tmp2 = (this->points[i].y - this->points[j].y);
+          tmp = sqrt (tmp1 * tmp1 + tmp2 * tmp2);
+          if (diag < tmp)
+            {
+              diag = tmp;
+            }
+        }
+    }
+
+  return diag;
 }
 
 /* public */
-Polygon* Polygon_new (const struct point *points)
+Polygon* Polygon_new (const struct point *points, int npoints)
 {
-
-}
-
-/* considered to be protected */
-void Polygon_constructor (Polygon *this, const struct point *points)
-{
-
-}
-
-void Polygon_destructor (Polygon *this)
-{
-
-}
-
-void Polygon_copy (Polygon *dest, const Polygon *src)
-{
-
+  Polygon *poly = g_new0 (Polygon, 1);
+  Polygon_constructor (poly, points, npoints);
+  return poly;
 }
diff --git a/Polygon.h b/Polygon.h
index 1176904..6f44adb 100644
--- a/Polygon.h
+++ b/Polygon.h
@@ -22,6 +22,8 @@ typedef struct Polygon
   } *vtable;
 
   /* Polygon fields */
+  int npoints;
+
   struct point
   {
     double x, y;
@@ -30,7 +32,7 @@ typedef struct Polygon
 
 } Polygon;
 
-Polygon* Polygon_new (const struct point *points);
+Polygon* Polygon_new (const struct point *points, int npoints);
 
 static inline const char* Polygon_type (const Polygon *this)
 {
@@ -63,7 +65,7 @@ static inline double Polygon_max_diag (const Polygon *this)
 }
 
 /* considered to be protected */
-void Polygon_constructor (Polygon *this, const struct point *points);
+void Polygon_constructor (Polygon *this, const struct point *points, int npoints);
 void Polygon_destructor (Polygon *this);
 void Polygon_copy (Polygon *dest, const Polygon *src);
 
diff --git a/Rhomb.c b/Rhomb.c
index 3a21248..9510730 100644
--- a/Rhomb.c
+++ b/Rhomb.c
@@ -37,13 +37,13 @@ static int __Rhomb_is_square (const Rhomb *this)
 }
 
 /* public */
-Rhomb* Rhomb_new (const struct point *points)
+Rhomb* Rhomb_new (const struct point *points, int npoints)
 {
 
 }
 
 /* considered to be protected */
-void Rhomb_constructor (Rhomb *this, const struct point *points)
+void Rhomb_constructor (Rhomb *this, const struct point *points, int npoints)
 {
 
 }
diff --git a/Rhomb.h b/Rhomb.h
index 5ba5c0b..96907bb 100644
--- a/Rhomb.h
+++ b/Rhomb.h
@@ -25,11 +25,13 @@ typedef struct Rhomb
   } *vtable;
 
   /* derived from Polygon */
+  int npoints;
+
   struct point *points;
 
 } Rhomb;
 
-Rhomb* Rhomb_new (const struct point *points);
+Rhomb* Rhomb_new (const struct point *points, int npoints);
 
 static inline const char* Rhomb_type (const Rhomb *this)
 {
@@ -67,7 +69,7 @@ static inline int Rhomb_is_square (const Rhomb *this)
 }
 
 /* considered to be protected */
-void Rhomb_constructor (Rhomb *this, const struct point *points);
+void Rhomb_constructor (Rhomb *this, const struct point *points, int npoints);
 void Rhomb_destructor (Rhomb *this);
 void Rhomb_copy (Rhomb *dest, const Rhomb *src);