A presentation on the Budapest Seminars in Mathematics Education website, inspired the author to try a new approach while teaching a unit on quadrilaterals in his Geometry for K-8 Teachers course, a class primarily composed of undergraduate students interested in teaching at the elementary or middle school level. The author designed a lesson that culminated in an exploration, after which students were able to answer the question of "which special quadrilaterals have congruent bisecting diagonals?" and justify their answers. The inspiration came from the following problem, which can also be found at https://bsmeducation.com/ about/wolves-and-sheep/: There are wolves and sheep. A sheep is eaten by any wolf that is closest to it. But if there are multiple wolves that are the same distance from a sheep, they do not eat the sheep. After students acted out the problem in class, they gathered in small groups. The teacher gave poker chips to each group to symbolize wolves and coins to symbolize sheep and then posed a number of questions: (1) Where are the sheep safe if three wolves stand at the vertices of a triangle; (2) Where are the sheep safe if four wolves stand at the vertices of a rectangle, parallogram, or trapeziod; (3) Where are the sheep safe if there are two lines of wolves; and (4) Find an arrangement of infinitely many wolves in which there is no safe place for sheep. The author writes that this task fit well into his class because it engaged students in a problem-solving task that promoted multiple solution strategies and required them to grapple with the relationship between key mathematical ideas.