https://decimal-to-binary.com/ploschad-parallelepipeda.html?id=4

Surface area of a parallelepiped with edges a = 0.86, b = 0.191, c = 0.84 equal to 2.094

Method of calculating the area of a parallelepiped:
Edge length a: Edge length b: Edge length c:

rectangular parallelepiped

A rectangular parallelepiped is a geometric shape in which all six faces are rectangles
Parallelepiped surface area formula Parallelepiped surface area formula By the length of the ribs where a,b,c are the lengths of the edges

Solution:
S = 2·(ab+bc+ca)
= 2·(0.86·0.191+0.191·0.84+0.84·0.86)
= 2·(0.16426+0.16044+0.7224)
= 2·1.0471
=
2.094

a: Surface area of a parallelepiped with edges a = 0.86, b = 0.191, c = 0.84 equal to 2.094