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
Answer:
Your question cannot be correct
Step-by-step explanation:
A line passing through points (6,6) and (6,1) cannot have a slope of 5.
This line passing through these two points would be a vertical line. The slope of a vertical line is considered UNDEFINED.