tolong jawab..........

11.bangun 1.=1/2×phi×r kuadrat
=1/2 ×22/7×7 kuadrat
=1/2×22/7×49
=77cm
Bangun2.=1/2×phi×r kuadrat
=1/2×22/7×7 kuadrat
=1/2×22/7×49
=77cm
Bangun3.=1/2×phi×r kuadrat
=1/2×22/7×14 kuadrat
=1/2×22/7×196
=308cm
Luas bangun seluruhnya=77+77+308
=462cm
12.bangun 1.=s×s
=20m×20m
=400m
Bangun 2.=1/2×a×t
=1/2×20×8
=80m
Bangun 3.=1/2×phi×r kuadrat
=1/2×3,14×10 kuadrat
=1/2×3,14×100
=157m
Luas bangun yang diarsir=400m-80m-157m
=163m