please bantu Jawab pelajaran guru KILLER besok harus dikumpulkan!!pakai cara

8/12 = 6/a
12×6 =8×a
72 = 8a
a = 72/8
a = 9
maaf kalau jawabannya salah

[tex] \frac{8}{12} = \frac{6}{a} \\ \frac{2}{3} = \frac{6}{a} \\ 2a = 6 \times 3 \\ 2a = 18 \\ a = \frac{18}{2} \\ a = 9 \: cm[/tex]
semoga membantu.....