Jawabanmu

2014-05-29T19:14:01+07:00
K segitiga = AB+AC+BC
40 = 15+15+BC
40 = 30 + BC
40-30 = BC
10 = BC
1 2 1
2014-05-29T19:14:28+07:00
Keliling = AB + AC + BC
BC = keliling - ( AB + AC )
BC = 40 - (15+15)
BC = 40 - 30
BC = 10 cm