Each edge is given by the distance formula, which is the Pythagorean Theorem. When one of the coordinates is the same, we can shortcut that.
A(−2, 1) , B(−2, 7), C(1, 11), D(4, 7), E(4, 1)
[tex]AB=7-1=6[/tex]
[tex]BC=\sqrt{(1 - -2)^2 + (11-7)^2}=5[/tex]
[tex]CD=\sqrt{(4 - 1 )^2 + (11-7)^2}=5[/tex]
[tex]DE=7-1=6[/tex]
[tex]EA= 4 - -2 = 6[/tex]
[tex]\textrm{perimeter} = 6+5+5+6+6=28[/tex]
Answer: 28
