Jawabanmu

2014-04-14T19:39:43+07:00
La= a x t : 2
108= 18 x t :2
18t=108 x 2
18t=206
t=12 cm
kel segitiga= 12 + 12 +18 cm=42 cm
2014-04-14T19:39:43+07:00
Luas = 1/2 × a × t
108 cm² = 1/2 × 18 × t
108 × 2 ÷ 18 = t
12 cm = t

sisi miring = √12² + 9² = √144 + 81 = √225 = 15 cm

keliling = 18 + 15 + 15 = 48 cm