3.13. The volume of a convex polyhedron is $V$, the surface area is $S$; the length of the $i$-th edge is $l_{i}$, the dihedral angle at this edge is $\varphi_{i}$. Consider the body consisting of points that are at a distance not greater than $d$ from the polyhedron. Find the volume and surface area of this body.
3.13. As in the previous problem, we will divide the obtained body into the original polyhedron, prisms corresponding to the faces, parts of cylinders corresponding to the edges, and parts of a sphere of radius $d$ corresponding to the vertices. Now it is easy to check that the volume of the obtained body is equal to $V+S d+\frac{1}{2} d^{2} \sum_{i}\left(\pi-\varphi_{i}\right) l_{i}+$ + $\frac{4}{3} \pi d^{3}$, and the area of its surface is equal to $S+d \sum_{i}\left(\pi-\varphi_{i}\right) \times$ $\times l_{i}+4 \pi d 2$