Jawabanmu

2014-06-15T06:14:24+07:00
1cm = 400
atas = 7 x 400 = 2800
bawah = 4 x 400 = 1600
tinggi = 3 x 400 = 1200

luas = 1/2 x (a+b)xt
Luas= 1/2 x (2800+1600) x 1200
luas = 1/2 x (4400) x 1200
Luas = 2200 x 1200 = 2.640.000

2014-06-15T06:15:10+07:00
Tinggi = 3 × 400 = 1.200 cm = 12 m Sisi sejajar a = 4 × 400 = 1.600 cm = 16 m Sisi sejajar b = 7 × 400 = 2.800 cm = 28 m Luas = 1/2 × (16 + 28) × 12 = 264 m persegi