Finished

 So here is the secret - and it is what is fun about turtle - a goto is a forward

command. If the pen is up, nothing shows; but if pen is down, there is a line.

Below, I have removed the i in range(10) loop, so turtle is only doing a double.

The first triangle is completed because turtle subsequently returns to the center. 

The second is not because its work is finished...

                                                                       

                                                                              

                                                  

Another nice touch: the little knots in the circle. The original code calls for 4. 

Below, I have reduced it to 3. Not so cute...

                                                                      

*     *     *

With numbers for a smaller screen:

                                                                        

                                                                              

                                                                         

                                                                          

Then, moving the side decos up by thirty, and the right over by 10...