Lesson Plan

# World's Largest Sierpinski Triangle

Victor Donnay
Department of Mathematics
Bryn Mawr College

## Goal

To foster group spirit throughout the school by having students from all class cooperate to build the world's largest Sierpinski triangle.

Have the students make a colored Sierpinski triangle as we did. Then take three triangles and paste (glue or tape) them together to make a larger triangle. Take three of these larger triangles and paste them together. Repeat. In this way, combine all the triangles made by the students in the class into one large triangle. Have several classes (all the classes in the school!) do this. Then take the huge triangles from each class and combine them.

## Enrichment Exercise

Have several schools do this project. Then have the schools meet at some large park and combine their triangles into one super huge triangle. Perhaps have all the schools in the Philadelphia school district involved. Think REALLY BIG! Get an aerial photograph of the resulting triangle with all the students standing around it.

Teach the students the Sierpinski triangle song:

Take each triangle
split it into 4
throw away the middle one
and keep the other 3.