Answers

2016-03-21T21:18:04+08:00
The surface area of a regular octahedron consists of
   8 equilateral triangles
        area of an equilateral  triangle    =     √3 a²/4
    thus    A  =  8 .  √3 a²/4           / a  = length of a side of the
                    =   2√3a²                            triangle
0