Tolong dijawab no 20
20. L arsir = L segitiga besar + L trapesium besar – 2 x L segitiga kecil
L segitiga besar = ½ x 16 x (4+8+10)
= ½ x 16 x 22 = 176 cm²
L trapesium = ½(16+14+20)x(10+8)
= ½ x 50 x 18
= 450 cm²
L segitiga kecil = ½ x 16 x 10 = 80 cm²
L arsir = 176 + 450 – 2 x 80
= 626 – 160 = 466 cm² (B)