A Math Forum Web Unit
Tom Scavo's

### Introduction

Materials
Length
Area
Pick's Theorem
Dot Paper
Epilogue

### Lessons

Lines
Squares
Rectangles
Parallelograms
Right Triangles
Bibliography

### To the teacher:

This unit deals with the length and area of two-dimensional geometric figures using the geoboard as a pedagogical device. Even though your students may have already seen some of this material, it is still likely that many of them have only a superficial understanding of length and area. It's quite amazing, for example, how many students have trouble distinguishing between perimeter and area - even secondary students confuse the two.

A typical student's understanding of units is even more problematic. Ask your students to describe a square inch, for example. It's unfortunate, but true, that many write "in2" without really understanding what it means. But with a geoboard, a student can see the area of a rectangle, say, and will readily count the square units making up such a geometric figure. Indeed, "square unit" takes on a whole new meaning with the geoboard.