Create shape and perimeter prototype

geometry.hs

@@ -1,6 +1,13 @@
 data Point = Point Float Float
 
+data Shape = Singularity Point | Circle Float Point | Square Point Point
+
 distance p1 p2 = 
 	let (Point a b) = p1 in
 		let (Point c d) = p2 in
 			sqrt ((a - c) * (a - c) + (b - d) * (b - d))
+
+perimeter sh = case sh of
+	Singularity _ -> 0.0
+	Circle _ _ -> 1.0
+	Square _ _ -> 2.0