keliling persegi panjang60 cm.panjang 18 cm.berapa lebar persegi panjang tersebut

Rumus keliling = 2 (p + l) = 60
jadi
p + l = 60 : 2
p + l = 30
18 + l = 30
l = 30 -18
l = 12 cm

K = 2p+2l
60 = 2x18+2l
60 = 36 +2l
24 = 2l
l = 12cm

L = p x l
L= 18 x 12
L = 219cm²

p: panjang, l: lebar, K: keliling, L: lebar