Answer:
[tex]\Large \boxed{\sf \ \ 4\sqrt{a^2+b^2} \ \ }[/tex]
Step-by-step explanation:
Hello,
You can use Pythagoras in the 4 right triangles.
For one triangle it comes [tex]\sqrt{a^2+b^2}[/tex].
Then for the polygon it gives [tex]4\cdot \sqrt{a^2+b^2}[/tex].
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
