luas daerah yang diarsir adalah ...cm2

L1 = ½ × a × t
L1 = ½ (12) × (10 + 12 + 6)
L1 = 6 × 28
L1 = 168 cm²

L2 = ½ × a × t
L2 = ½ (12) × 6
L2 = 6 × 6
L2 = 36 cm²

L3 = ½ × a × t
L3 = ½ (12) × (12 + 6)
L3 = 6 × 18
L3 = 108 cm²

L.arsir = L1 + L3 - (2 × L2)
L.arsir = 168 + 108 - (2 × 36)
L.arsir = 276 - 72
L.arsir = 204 cm² ✔