Re: The octahedron shown above is a solid figure whose eight equal faces

Alternate Method Visualization

2 equilateral triangles + 2 more edges on the upper half of octahedron.
And, 4 more edges in lower half

oSo, if we combine the extra 2 edges of upper half into 4 edges of lower half, we will get 2 equilateral triangles in upper half and 2 in lower half.
oThus, 4 equilateral triangles.
Total length = Perimeter of 1 triangle * 4 = 5*4 = 20