Answer:
11.5214512633
Step-by-step explanation:
Add up all the sides, using Pythagorean theorem for each side by finding the difference in horizontal and vertical coordinates.
CD: [tex]\sqrt{\left(2-\left(-1\right)\right)^{2}+\left(\left(-1\right)-\left(-2\right)^{2}\right)}[/tex] = 2
CF: [tex]\sqrt{\left(1-2\right)^{2}+\left(1-\left(-1\right)\right)^{2}}[/tex] = 2.2360679775
EF: [tex]\sqrt{\left(2-1\right)^{2}+\left(-2-1\right)^{2}}[/tex] = 3.16227766017
DE: [tex]\sqrt{\left(2-\left(-2\right)\right)^{2}+\left(\left(-2\right)-\left(-1\right)\right)^{2}}[/tex] = 4.12310562562
add them all up 11.5214512633
