Jawabanmu

2014-05-29T21:47:29+07:00
Luas = p * l = 90*50 = 4500 cm^2
Keliling = 2 * (p+l) = 2 * (90+50) = 2*140 = 280 cm

2014-05-29T21:48:39+07:00
Luas = p x l
          90 x 50 = 4500
keliling = 2(p+l) = 280