Online Course Discussion Forum

MC I-C problem 7.26

Picture of David Reynoso
Re: MC I-C problem 7.26
by David Reynoso - Monday, January 28, 2019, 12:11 PM

You just need to verify it. That is, you will need to count the number of faces ($F$), vertices ($V$), and edges ($E$) of the regular octahedron, and verify that indeed $V - A + F = 2$.

For this purpose a picture is not needed, since we know it is formed by $8$ equilateral triangles. (Think of two square pyramids glued together by their square faces.)