a) perimetru paralelogram = P = 2xL+2xl = 2x4,5+2x3,5 = 9+7 = 16 cm
b) P = 2x9√5+2x√180 = 18√5+2x√36x5 = 18√5+2x6√5 = 18√5+12√5 = 30√5 cm