Odpowiedź:
[tex]A=(-3,1)\ \ ,\ \ B=(1-2)\ \ ,\ \ C=(5,1)\ \ ,\ \ D=(1,3)\\\\\\|AB|=\sqrt{(x_{B}-x_{A})^2+(y_{B}-y_{A})^2}=\sqrt{(1-(-3))^2+(-2-1)^2}=\\\\=\sqrt{(1+3)^2+(-3)^2}=\sqrt{4^2+9}=\sqrt{16+9}=\sqrt{25}=5\\\\\\|BC|=\sqrt{(x_{C}-x_{B})^2+(y_{C}-y_{B})^2}=\sqrt{(5-1)^2+(1-(-2))^2}=\\\\=\sqrt{4^2+(1+2)^2}=\sqrt{16+3^2}=\sqrt{16+9}=\sqrt{25}=5\\\\\\|CD|=\sqrt{(x_{D}-x_{C})^2+(y_{D}-y_{C})^2}=\sqrt{(1-5)^2+(3-1)^2}=\\\\=\sqrt{(-4)^2+2^2}=\sqrt{16+4}=\sqrt{20}=\sqrt{4\cdot5}=2\sqrt{5}[/tex]
[tex]|AD|=\sqrt{(x_{D}-x_{A})^2+(y_{D}-y_{A})^2}=\sqrt{(1-(-3))^2+(3-1)^2}=\sqrt{(1+3)^2+2^2}=\\=\sqrt{4^2+4}=\sqrt{16+4}=\sqrt{20}=\sqrt{4\cdot5}=2\sqrt{5}\\\\\\Ob=a+b+c+d\\\\Ob=5+5+2\sqrt{5}+2\sqrt{5}=10+4\sqrt{5}[/tex]
