Question

GEOMETRY. PLEASE CHECK MY ANSWER! THANKS.

Answer 1

I'd solved it in the pic, and the answer is D. 20

Answer 2

This is simple.
we should have a knowledge of the Euler's Theorem/Euler's Formula
F+V=E+2
Basically states that:
# of Faces+ # of Vertices= # of Edges+2
12 + 10 = E + 2
(-2) + 22 = E + 2 (-2)
           20 = E

Yep, The answer is D. 20 edges