17
[tex]\it A'G=\dfrac{1}{3}\cdot AA'=\dfrac{1}{3}\cdot9=3\ cm\\ \\ \\ C'G=\dfrac{1}{3}\cdot CC'=\dfrac{1}{3}\cdot6=2\ cm\\ \\ \\ A'C'-linie\ mijlocie \Rightarrow A'C'=\dfrac{AC}{2}=\dfrac{8}{2}=4\ cm\\ \\ \\ \mathcal{P}_{A'GC'}=3+2+4=9\ cm\\ \\ \rule{110}{0.4}\\ \\ \\ AG=\dfrac{2}{3}\cdot AA'=\dfrac{2}{3}\cdot9=6\ cm\\ \\ \\ CG=\dfrac{2}{3}\cdot CC'=\dfrac{2}{3}\cdot6=4\ cm\\ \\ \\ AC=8\ cm\\ \\ \\ \mathcal{P}_{AGC}=6+4+8=18\ cm[/tex]
