Jawabanmu

2014-06-05T21:32:18+07:00
Panjang sisi b 16cm
255= [18+b] ×15 ÷ 2
255 × 2 ÷15 = 18 +b
34 = 18 + b
16 = b
2014-06-05T21:35:22+07:00
255 = 18 + Sb . 15 / 2
255 = 18sb . 7,5
18sb = 255 : 7,5 
18sb = 34
sb = 34 - 18
Sb = 16 cm