Now first we must remember the formula: V - E + F = 2
Now let us look at V. V is the number of vertices, shown below:
Now let us look at E. E is the number of edges, shown below:
Now let us look at F. F is the number of faces, shown below:
To finish up we should plug back into the formula: V - E + F = 2 and solve when V = 12, E = 30, and F = 20...we get 12 - 30 + 20 = 2. And this works
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