Since the angle decreases with distance, this method can only be used for nearby stars. The use of parallax is limited to stars that are closer to Earth than 300 light years. Assembly of materials can be done ahead of time by a student aide. This not only saves time, but allows you to check the placement of the protractors. Though no worksheet is included, you may wish to make a class set of the procedure.
Scale drawings can go on the same paper.
Caution students to avoid rotating the measurer when they raise it to eye level during the outside portion of this activity. 82-84 I. Assembly of Materials Push one of the thumbtacks through the sticky side of a piece of tape. The tape should be long enough to wrap around the meter stick. Repeat the procedure with the second tack, positioning it over the 10 cm mark of the metric ruler. Place a protractor over each tack.