Have you ever stared into an orchard as you passed it on the road? From one perspective, you see that the trees are planted in straight rows. But as you move to a different spot, all you see is a mass of trees. The main characters of this unit, Madie and Clyde, have planted an orchard. They want to know how long it will take before they can no longer see from the center of the orchard to the outside world. We begin this unit with a look at their overall problem, and then we examined some simpler cases. The topics covered in this unit include: