sisi alas =...... sisi atas =8m tinggi = 7m luas = 84m berapa kah panajang sisi alas tersebut ??. mohon pake cara yhh

luas=a+8:2*7
84=a+8:2*7
84:7=a+8:2
12x2=a+8
24-8=16 cm

trapesium = (a + b) × tinggi :2
84 = (a + 8) × 7 : 2
84 × 2 = (a + 8) × 7
168 = a + 8 × 7
a + 8 = 168 ÷ 7
a + 8 = 24
a = 24 - 8 = 16

jadi a = 16 cm

semoga membantu ^^