In this app, will be able to find the volume of one of the legs of the seastar. You will then find the volume of all the legs to find the approximate volume of the seastar. To find the volume around the x-axis you have to use the function integral between 2 and 0 on the line .25sqrt(x)dx When you plug this into your calculator you will find that this equals .471. Then when it is multiplied by 5, you should get 2.357. If you use a limits other than 0 and 2 you will get other volumes.