tolong pakai cara ya no 18-19

18). Lpp = Lp
p x l = 225
25 x l = 225
l = 225/25
l = 9 cm

Kpp = (2 x p) + (2 x l)
Kpp = (2 x 25) + (2 x 9)
Kpp = 50 + 18
Kpp = 68 cm

19). Lp = Lpp
s x s = p x l
12 x 12 = 18 x l
144 = 18 x l
18 l = 144
l = 144/18
l = 8 cm