Answer:
The second graph.
Step-by-step explanation:
The one where the line is curving upwards.
Answer:
I think you forgot the context or image of that.
Euler's formula for a polyhedron is given by:

Make E, the subject of the formula:

Put F = 20, V = 12, to obtain E,

Therefore, there are 30 edges
the opposite is squared so,
square root of 4 is 2 and 2 squared is 4