diff -r 50d3086070df -r 1dc58f44d556 geometry.py
--- a/geometry.py	Sun Dec 10 15:46:47 2017 +0200
+++ b/geometry.py	Mon Dec 11 00:46:35 2017 +0200
@@ -11,12 +11,18 @@
             (self.y - other.y) ** 2 +
             (self.z - other.z) ** 2
         )
+    @property
+    def coordinates(self):
+        return self.x, self.y, self.z
 
 class LineSegment:
     def __init__(self, v1, v2):
         self.v1, self.v2 = v1, v2
     def __repr__(self):
         return str.format('LineSegment({!r}, {!r})', self.v1, self.v2)
+    @property
+    def vertices(self):
+        return self.v1, self.v2
 
 class Polygon:
     def __init__(self, vertices):