Tolomg dijawab pliss buat un nanti beserta caranya terima kasih

semoga bermanfaat ya....

cari SR dulu
SR/20 = 18/30
SR = 12
trus cari tinggi
t/15 = 18/30
t = 9
Ltb = 1/2(30+20)15
Ltb = 375 m2 = 3750000 cm2
Ltk = 1/2(18+12)9
Ltk = 135 m2 = 1350000 cm2
Lpp = 20*10
Lpp = 200 cm2
(Ltb - Ltk)/Lpp
3750000-1350000/200= 12000
jdi bnyak kramik adl 12000