For the 3D challenge
(previously known as Part 1) students can use the large protractor placed on the floor below the stationary mirror.
Most protractors are marked 0 degrees at one end, 90 degrees at the center and 180 degrees at the opposite end.
This protractor is marked with 0 degrees at the center, and with increasing angle measurements on the left and right sides. The wall would be 90 degrees.
Dividing the protractor this way helps students visualize an angle of incidence and angle of reflection when they plan where they should stand.
This paper protractor will have an 80 cm (31 1/2 inch) radius. See the competition described in the rules.
It’s relatively easy to make your own practice protractor. Or you can ** click here to download a .pdf file (actual size) of the 80 cm protractor used at the tournament. ** You are free to download, print and distribute this image without restriction.
If you visit the the print counter at "Office Depot / Office Max", they can make a full size b&w plot of this file for about $10.
Be sure to ask for "economy bond black line".
If you decide to have it laminated, expect to pay about $32.