save project

my_tree.py

@@ -12,4 +12,22 @@ pen.up()
 pen.backward(150)    # 后退
 pen.down()
 
+def tree(a):
+    pen.forward(a)
+    pen.right(30)
+    pen.forward(a/2)
+    pen.penup()
+    pen.backward(a/2)
+    pen.pendown()
+    pen.left(60)
+    pen.forward(a/2)
+    pen.penup()
+    pen.backward(a/2)
+    pen.right(30)
+    pen.backward(a)
+    pen.pendown()
+    
+tree(100)
+
 turtle.done()
+