Title: (Task) Billiards and Similarity
Course: HBUHSD Geometry Resource Course

Estimated Time: 30 minutes

Teacher's Notes: Standard G-SRT.5 calls for students to "use congruence and similarity criteria for triangles to solve problems." This task asks students to use similarity to solve a problem in a context that will be familiar to many, though most students are accustomed to using intuition rather than geometric reasoning to set up the shot.

In order to solve this problem, students must use the fact that when an object bounces off of a wall, the angle of incidence equals the angle of reflection; that is, the angle at which the object hits the wall is equal to the angle at which the object ricochets from the wall. Students who have not taken a physical science course may need to be given this fact (or asked to conjecture it after thinking about several examples of collisions).

Bank Shot - Similarity Task.pdf

Teacher Commentary and Solutions