



 
Hi Rukshanth, According to Wolfram Math World "The diagonal of a polyhedron is any line segment connecting two nonadjacent vertices of the polyhedron." A cube has 6 faces and on each face there are two diagonals joining nonadjacent vertices and there are 4 diagonals that run through the body of the cube. Thus in total there are $6 \times 2 + 4 = 16$ diagonals in a cube. Harley  


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