diff --git a/math/pythagoras.py b/math/pythagoras.py
new file mode 100644
index 000000000..6697e4d3c
--- /dev/null
+++ b/math/pythagoras.py
@@ -0,0 +1,16 @@
+"""
+input two of the three side in right angled triangle and return the third. use "?" to indicate the unknown side. 
+"""
+
+def pythagoras(opposite,adjacent,hypotenuse):
+	if opposite == str("?"):
+		print ("Solving for opposite")
+		return ((h**2) - (a**2))**0.5
+	elif adjacent == str("?"):
+		print ("Solving for adjacent")
+		return ((h**2) - (o**2))**0.5
+	elif hypotenuse == str("?"):
+		print ("Solving for hypotenuse")
+		return ((o**2)+(a**2))**0.5
+	else:
+		return "you already know the answer!"