I have a photo of what to do here, but i’ll still explain. First, we get the measurement for the top of B. To get this, we subtract 60 by 24, which is 36. To get the length (or the height), we add 36, 36, and 24 together and get 96, which we then subtract with 144. We then get 48. Now that we have the numbers, we then do base x height. Then we get our answer.