1A20.XX Triangulation

Concepts

Triangulation

Overview

The distance across the lecture hall is measured using triangulation. The apparatus is relatively large, but details, such as the meter stick, cannot be seen from far away.

Details

Equipment

  • [1] Triangulation board (mounted on a frame)
  • [1] Laser pointer (mounted on an arm)
  • [1] Paper bullseye
  • [1] Masking tape
  • [1] Stepping stool
  • [1] Metre stick
  • [1] 30 m measuring tape

Classroom Assembly

  1. Move the laser pointer arm to the top of the triangulation board and adjust the arm so it is horizontal.
  2. Record the height of the laser pointer arm at the pivot point using the metre stick.

Important Notes

  • Do not shine the laser pointer at the audience. Do not look directly into the laser beam.
  • The distance between the horizontal black lines on the triangulation board is 0.7 m.
  • The distance between the laser pointer arm's pivot point and the scale at the tip is 0.8 m.

Script

  1. Turn on the laser pointer and tape the paper bullseye to the wall so that the laser beam is centered in the bullseye.
  2. Lower the laser pointer arm.
  3. Record the height of the laser pointer arm at the pivot point using the metre stick.
  4. Tilt the laser pointer arm up until the laser beam is centered in the bullseye.
  5. Record the height of the tip of the laser pointer arm (i.e. the end furthest from the pivot point) using the metre stick.
  6. Calculate the distance from the laser pointer to the bullseye using the worksheet below (or click here for a print friendly version).
  7. Measure the distance from the laser pointer to the bullseye using a measuring tape to confirm your results.

 

Additional Resources

Triangulation Worksheet

References

  • PIRA 1A20.XX

Disclaimer

  • Don't attempt this at home!

Last revised

  • 2018

Technicals

Original construction: made in-house.

Related AV

Related demos

If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.