Step-by-step explanation:
Here
Now,
[tex]\\ \tt\hookrightarrow AB=\sqrt{(-2-1)^2+(6-2)^2}[/tex]
[tex]\\ \tt\hookrightarrow AB=\sqrt{(-3)^2+(4)^2}[/tex]
[tex]\\ \tt\hookrightarrow AB=\sqrt{9+16}[/tex]
[tex]\\ \tt\hookrightarrow AB=\sqrt{25}=5units[/tex]
And,
[tex]\\ \tt\hookrightarrow BC=\sqrt{1+2)^2+(2+2)^2}[/tex]
[tex]\\ \tt\hookrightarrow BC=\sqrt{(3)^2+(4)^2}[/tex]
[tex]\\ \tt\hookrightarrow BC=\sqrt{9+16}[/tex]
[tex]\\ \tt\hookrightarrow BC=\sqrt{25}=5units[/tex]
And
[tex]\\ \tt\hookrightarrow AC=\sqrt{(-2+2)^2+(6+2)^2}[/tex]
[tex]\\ \tt\hookrightarrow AC=\sqrt{(0)^2+(8)^2}[/tex]
[tex]\\ \tt\hookrightarrow AC=\sqrt{8^2}=\sqrt{64}=8units[/tex]
Now
[tex]\\ \tt\hookrightarrow perimeter=5+5+8=18units[/tex]