The volume of a rectangular parallelepiped 350 is two edges 7 and 10, find the area of the side surface.

First, let’s find the relationship between what we know and what we need to find.
Vpar = S main * h
S side pov = 2 (ac + bc)
S main = ab
Now let’s estimate what we know to find the side of the surface and what we need to find. We know the sides a = 7 b = 10 must be found with c = h in a rectangular parallelepiped
V = 350 whence Soсн * h = 350
350 = 7 * 10 * h
h = 350: 70
h = 5
Substitute in the formula
S side main = 2 (5 * 7 + 5 * 10) = 2 (35 + 50) = 85 * 2 = 170