# Using the Geoboard

Henri Picciotto

The geoboard provides a nicely constrained environment for mathematical exploration, and lends itself to many activities where students can discover or apply important ideas in the K-12 curriculum. This page is a hopefully comprehensive list of links to geoboard activities on this site and on my blog.

All activities I link to below can be done on the CircleTrig Geoboard, a two-sided manipulative I designed. On one side, an 11 by 11 traditional geoboard. On the other side, a circle geoboard, with radius 10 cm, and a 360° protractor. It is available from Nasco.

(However, most can be done on traditional 11 by 11 geoboards, or traditional circle geoboards.)

Compact introduction to the geoboard for teachers: one page | two pages

## 11 by 11 Geoboard

### Geometry Labs(free download)

Area: Labs 8.4-8.6, 9.5
Distance: Labs 9.2, 9.4, 9.6
Similarity, Slope: Labs 10.1, 10.2

### Algebra: Themes, Tools, Concepts(free download)

(Some of these lessons overlap and complement the ones in Geometry Labs)
Area: Lessons 1.12, 2.12, 4.12, 6.12, 11.A
Distance, Square Roots Lessons 6.12, 7.12, 9.1-9.4, 9.A, 9.9, 9.C,
Similarity, Slope: Lessons 3.12, 8.3, 11.3

### Blog posts

Geoboards and Dot Paper
Geoboard Triangles
Inscribing Geoboard Squares in Polyominoes
No Three on a Line
Heilbronn's Triangle
Ariadne's String
Geoboard Problems for Teachers

### On this site

A debate about the geoboard
Proving Pick's Formula
Dot Papers
Connecting the Dots! (presentation slides): html | PDF | Keynote

## Circle Geoboard

### Geometry Labs(free download)

Angles: Labs 1.7-1.9
Symmetry: Lab 5.5
Area: Labs 9.5, 11.7
Basic trig: Labs 11.1-11.7
(All but the trig activities can be done on any circle geoboard. The trig activities require the CircleTrig geoboard.)

### On this site

(excerpts from Geometry Labs)
Angles
The 10cm Circle
10-cm circle paper