Jawabanmu

2014-05-25T18:19:04+07:00
L = 2×((p×l)+(p×t)+(l×t)) 258 = 2×((9×5)+(9×t)+(5×t)) 258 = 2×((45)+(9t)+(5t)) 258 = 2×(45+14t) 258 = 90 + 28t 28 t = 168 t = 6 cm
2014-05-25T18:28:31+07:00
L balok= 2pl+2pt+2lt
258 =2×(9×5)+2×(9×t)+2×(5×t)
258 =2×45 +2×9t+2×5t
258 = 90+18t+10t
258=90+ 18t
258-90=18t
168=18 t
t=168:18
t=9,3333333