Let the be the time in hours, and meters of fencing completed.
We know that After three hours, they have 15 meters of fencing complete, our graph will go from the point (0,0) to the point (3,15). We also know that they decide to take a 2-hour break for lunch and then resume building the fence, so our graph will go from the point (3,15) to the the point (5,15). Finally, After four more hours, they have a fence that is a total of 55 meters long, so the final part of our graph will go from the point (5,15) to the point (9,55)
We can conclude that the graph of t vs y is:
