Wow! You just noticed that your superhero copied a triangle from his workbook and it is very close to perfection. Sure, you cannot control your happiness and you must be appreciating your child for this act!
What you need to know:
The perfection that he has shown is a sign of his developing eye-hand coordination. Now, he is able to look at one thing and use his hands to copy it at the same time. This is directly related to mind development and a step further in his overall growth. The eye-hand movement he has shown is exemplary and you will get to see more of it in the coming months.