Since the ratio of the sides is 5:3, the sides are 5x and 3x centimeters long, where x is the common factor. For the area we have 5x*3x = 15x^2 = 375, so x^2 == 25; therefore, x= = 5. Thus the sides are 5*5 = 25 cm and 3*5 = 15 cm long. The perimeter is 25 + 15 + 25 + 15 = 80 cm. ANSWER