Now it's time to build your solid. 1. 2. For simplicity, decide whether you want to use circles, squares, or rectangles. Cut out at least ten different circles (or squares or rectangles). Each one should be a different size, with the largest no bigger than 20 cm or so in diameter, but all should be same shape. More than ten is even better. . Stack the cardboard shapes with the largest on the bottom to the smallest on the top. If you used circles, your solid will look a little like a cone. If you used squares or rectangles, your solid will look like a pyramid. Now, slide the cardboard cross sections around slightly to create a weird, irregularly stepped cone or pyramid. Notice that if you slide them too much, it stops looking like a solid and starts looking like a pile of cardboard trash! You can also try mixing them up so the. no longer go from largest to smallest. When you've made an irregular solid you like (and that doesn't look like a messy stack of cardboard), glue the cross sections in place. Calculate its volume. Imagine your solid all smoothed out, so it no longer has "steps." 15 the calculation you made in step 5 a good approximation for the volume of this smooth, imaginary shape