oblicz pola zacieniowanych figur proszę szybko

a)
P1 = 3×3 = 9 (j2)
P2 = 2×5 = 10 (j2)
P3 = 4×8 = 32 (j2)
P = 9+10+32 = 51 (j2)
b)
P1 = 7×11 = 77 (j2)
P2 = 7×5 = 35 (j2)
P3 = 6×3 = 18 (j2)
P = 77+35-18 = 112-18 = 94 (j2)