Teaching Tips: The Angle on Pool

After the video

• Have students discuss how they would use the law of reflection to help determine the point on the rail to hit for a bank shot. Draw a scenario on the board showing a rectangular pool table, a target ball placed near a pocket, and a cue ball. Have them draw lines on the board to help them figure out where the cue ball should bounce off the rail in order to hit the target ball into the pocket.
• Have students prove geometrically or algebraically why the cue ball's path after hitting the rail is symmetrical to its incoming path.
• Discuss how the 90-degree angle on the table would look different from certain perspectives. Have students use the board to draw a bird's-eye view of the 90-degree angle created by the pool balls. Ask students to consider how the same shot would look from various positions, such as:
  • Eye level with the table
  • Standing eye level (seen in the video)
• If you have access to a pool table, have students work in small groups to demonstrate the 90-degree rule and the law of reflection. Encourage them to think through the angles carefully before taking a bank shot. You may want to have them cover the balls in chalk so that the tracks will be visible after each hit. They can then measure the angles with a protractor.