tolong jawab nomor 21 dan 22

21.L1=1/2×a+b×t
=1/2×60+40×20 L1+L2=1000+600
=50×20=1000 =a.1600
L2=p×l=60×10=600

22.L1=1/2×a×t
=1/2×25×14
=175 L1+L2=175+625
L2=s×s =a.800
=25×25
=625