Chapter 9, Lesson 1
Today, David and Ruth had an introduction to a branch of mathematics called topology. They learned that:
A network is a figure consisting of points (vertices) connected by lines (straight or curved, called arcs).
You can travel a network when is possible to draw the figure without retracing any line or taking your pencil off the paper.
David thinks that of the two networks shown below, only the one at the left can be traveled. Ruth thinks that both of these networks can be traveled. With whom do you agree? Explain; include the details of your path.