diff --git a/src/tools/coordinate.py b/src/tools/coordinate.py
index dce56dc..1e1a2d0 100644
--- a/src/tools/coordinate.py
+++ b/src/tools/coordinate.py
@@ -2,7 +2,7 @@ from __future__ import annotations
 from enum import Enum
 from math import gcd, sqrt, inf, atan2, degrees, isclose
 from .math import round_half_up
-from typing import Union, List
+from typing import Union, List, Iterable
 from .tools import minmax
 
 
@@ -379,6 +379,16 @@ class Shape:
     def __rand__(self, other):
         return self.intersection(other)
 
+    def __contains__(self, item: Coordinate) -> bool:
+        if not self.mode_3d:
+            return self.top_left.x <= item.x <= self.bottom_right.x and self.top_left.y <= item.y <= self.bottom_right.y
+        else:
+            return (
+                self.top_left.x <= item.x <= self.bottom_right.x
+                and self.top_left.y <= item.y <= self.bottom_right.y
+                and self.top_left.z <= item.z <= self.bottom_right.z
+            )
+
     def __str__(self):
         return "%s(%s -> %s)" % (
             self.__class__.__name__,
@@ -394,9 +404,9 @@ class Shape:
         )
 
 
-class Square(Shape):
+class Rectangle(Shape):
     def __init__(self, top_left, bottom_right):
-        super(Square, self).__init__(top_left, bottom_right)
+        super(Rectangle, self).__init__(top_left, bottom_right)
         self.mode_3d = False
 
 
@@ -407,6 +417,7 @@ class Cube(Shape):
         super(Cube, self).__init__(top_left, bottom_right)
 
 
+# FIXME: Line could probably also just be a subclass of Shape
 class Line:
     def __init__(self, start: Coordinate, end: Coordinate):
         if start[2] is not None or end[2] is not None:
@@ -422,12 +433,6 @@ class Line:
     def connects_to(self, other: Line) -> bool:
         return self.start == other.start or self.start == other.end or self.end == other.start or self.end == other.end
 
-    def contains(self, point: Coordinate | tuple) -> bool:
-        return isclose(
-            self.start.getDistanceTo(self.end),
-            self.start.getDistanceTo(point) + self.end.getDistanceTo(point),
-        )
-
     def intersects(self, other: Line, strict: bool = True) -> bool:
         try:
             self.get_intersection(other, strict=strict)
@@ -454,7 +459,7 @@ class Line:
         if not strict:
             return ret
         else:
-            if self.contains(ret) and other.contains(ret):
+            if ret in self and ret in other:
                 return ret
             else:
                 raise ValueError("intersection out of bounds")
@@ -462,11 +467,79 @@ class Line:
     def __hash__(self):
         return hash((self.start, self.end))
 
+    def __eq__(self, other: Line) -> bool:
+        return hash(self) == hash(other)
+
     def __lt__(self, other: Line) -> bool:
         return self.start < other.start
 
+    def __contains__(self, point: Coordinate | tuple) -> bool:
+        return isclose(
+            self.start.getDistanceTo(self.end),
+            self.start.getDistanceTo(point) + self.end.getDistanceTo(point),
+        )
+
+    def __len__(self) -> int:
+        return int(self.start.getDistanceTo(self.end))
+
     def __str__(self):
         return f"Line({self.start} -> {self.end})"
 
     def __repr__(self):
         return str(self)
+
+
+class Polygon:
+    def __init__(self, points: list[Coordinate]) -> None:
+        """points have to be in (counter)clockwise order, not repeating the first coordinate"""
+        if len(set(points)) != len(points):
+            raise ValueError("Polygon contains repeated points")
+
+        self.points = points
+        self.lines = set()
+        for i in range(len(points) - 1):
+            self.lines.add(Line(points[i], points[i + 1]))
+        self.lines.add(Line(points[-1], points[0]))
+
+    def get_circumference(self) -> float:
+        return sum(len(x) for x in self.lines)
+
+    def get_area(self) -> float:
+        S = 0
+        for i in range(len(self.points)):
+            S += (
+                self.points[i].x * self.points[(i + 1) % len(self.points)].y
+                - self.points[(i + 1) % len(self.points)].x * self.points[i].y
+            )
+
+        return abs(S) / 2
+
+    def decompose(self) -> Iterable[Rectangle]:
+        points_left = list(self.points)
+
+        def flip(point: Coordinate):
+            if point in points_left:
+                points_left.remove(point)
+            else:
+                points_left.append(point)
+
+        while points_left:
+            pk, pl, pm = None, None, None
+            for c in sorted(points_left, key=lambda p: (p[1], p[0])):
+                if pk is None:
+                    pk = c
+                    continue
+
+                if pl is None:
+                    pl = c
+                    continue
+
+                if pk.x <= c.x < pl.x and pk.y < c.y:
+                    pm = c
+                    break
+
+            flip(pk)
+            flip(pl)
+            flip(Coordinate(pk.x, pm.y))
+            flip(Coordinate(pl.x, pm.y))
+            yield Rectangle(pk, Coordinate(pl.x, pm.y))