Which of the following best describes an Euler Path

A path that goes through every EDGE once and starts and ends at different vertices.

Explanation:

A "Euler path" is a trail that is being used in a graph consisting of finite number of edges. It is also known as "Eulerian path." This should be contrasted from the "Euler circuit," for both of their meanings are a bit confusing.

A Euler path only uses every edge of the graph once and it starts and ends at different vertices. A Euler circuit, on the other hand, uses every edge of the graph exactly once but starts and ends at the same vertex.

So, this explains the answer.

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.