Return to Mathematics Index Williams, Gwendolyn D. Paul Robeson
High School To show the ratio of pi by revolving a circle one
complete time. The students will learn why the ratio is true. To
allow the students to do the same independent of the teacher's
You need: Two random size pieces of plexiglass. One screw (long
enough to pass through all thickness of the pieces you use) One
pair of nuts to hold the screw in place. One aluminum channel no
longer than four feet. To make the circle, cut either piece
first. Draw a circle on the paper covering of the plexiglass or
cut random tangents to a squared piece until it is it is
somewhat round. Drill a hole at the center of the piece large
enough to put your screw through. Finding the center should not
be a problem. Once the "round" piece is ready, sand out the
rough spots. Find a thick piece of wood that you can nail the
circle to . After nailing the circle to the wood, go to the
sander and rotate the plexiglass until the rough spots are gone.
Draw an arrow from the