Angles of Incidence and Reflection - Dec. 5-9, 1994 Blaise came into geometry class and dropped her physics notebook on the table. "I've got a problem from physics class, and I'm hoping our group can work on it today." Beltram, who was sitting in the group at the next table, said "Physics? What's that have to do with geometry?" "Hang on," said Mr. Bolyai, the teacher. "Let's hear what it is." "Okay," said Blaise. "Here's the deal. Today we learned that when light is bounced off a surface, the angle at which it hits, called the angle of incidence, is the same as the angle at which it bounces back, called the angle of reflection. So i = r. I asked how you prove that, and she told me I could probably do it myself. The only other thing I know is that light takes the shortest possible path, so if it's going from P to Q in this picture, it's going to take the shortest path it can." "Sure looks like geometry to me!" agreed Beltram. Correct solutions to the problem were submitted by: Pawel Gobis and Imran Hayat, Burnaby South Secondary School Simone George, College Park High School Andrew Liu, College Park High School Susie Goetz, College Park High School Kristina Almquist, College Park High School Faaiza Bashir, College Park High School Stephen Switzer, College Park High School Sean Nichols, Burnaby South Secondary School Anita Lau, Burnaby South Secondary School Pat Daley's calculus class with special insight from Kiki David, Jessica Nahabedian, Adam Smith, Christina Smith, and Tom Soper, Fairfield HS Leigh Jeitner, Mt. St. Joseph's Susanna Puntel, Mt. St. Joseph Academy Sarah Egner, Mt. St. Joseph's Kim Biedermann, Mt. St. Joseph Academy Next problem || Previous problem || Table of Contents || Forum Home Page