Answer:
Step-by-step explanation:
Using the distance formula,
[tex]AB=\sqrt{(-11-(-7))^{2}+(4-8)^{2}}=\sqrt{16+16}=4\sqrt{2}\\AC=\sqrt{(-11-(-4))^{2}+(4-4)^{2}}=7\\BC=\sqrt{(-7-(-5))^{2}+(8-4)^{2}}=\sqrt{4+16}=2\sqrt{5}\\\\[/tex]
So the perimeter is [tex]4\sqrt{2}+7+2\sqrt{5}[/tex]