You also could Pick Numbers on this problem. Choose a value for x and then find the volume
and the value of d. Plug d into the answer choices and see which one matches.3 . D
When a cube of edge length b is divided into 8 identical smaller cubes, the edge of each of
the smaller cubes is .
The surface area of the original cube is 6 × b × b = 6b^2 . The surface area of one of the smaller
cubes isor . There are eight small cubes, so their combined surface area is . The
difference is 12b^2 – 6b^2 = 6b^2.4 . D
When you write the equations for the volumes, try to plug in the area of the triangle, since
that is known.
When you rotate a right triangle about a leg, you get a cone:One leg becomes the base radius, and the other becomes the height of the cone. Call the
short leg a and the long leg b and plug them into the cone volume formula:It’s also given that the area of the right triangle is 4. Therefore,