Okay, i went with a rectangle, if the rectangle base is 12 and the height is 6 then it would be 12*6 + 12*6 + 12*6= 216 now the ratio is easy , 72:72 because that's what makes up the 12*6 and because there is 3 it's 72 two times now for part b 5 x 10 so that is the height and length so now what you want to do is do what you did the second time so it would be 72:50. Extra tips: To find the volume of any cube you need to know the length, width and height. The formula to find the volume multiplies the length by the width by the height. The good news for a cube is that the measure of each of these dimensions is exactly the same. Therefore, you can multiply the length of any side three times.