tolong bantu dengan cara nya ya !makasii!

LΔ = 1/2*a*t
L¹ = 1/2*20*(5+3+6) = 1/2*20*14 = 140 cm²
L² = 1/2*20*(5+3) = 1/2*20*8 = 80 cm²
L³ = 1/2*20*5 = 50 cm²
L yg diarsir = L¹+L²-(2*L³) = 140+80-(2*50) = 220-100 = 120 cm² (A)