Question 419059
Euler's formula states that:


V - E + F = 2


see the following reference:


<a href = "http://www.math.osu.edu/~fiedorow/math655/Euler.html" target = "_blank">http://www.math.osu.edu/~fiedorow/math655/Euler.html</a>


You have:


V = 16
F = 17
E = ?????


V - E + F = 2 becomes:


16 - E + 17 = 2


Add E to both sides of this equation and subtract 2 from both sides of this equation to get:


16 + 17 - 2 = E


Combine like terms to get:


31 = E


Number of edges should be equal to 31.