Rediscovering the patterns in Pick's Theorem
http://illuminations.nctm.org/LessonDetail.aspx?ID=L623
A lesson plan for Grades 9–12 Algebra 1
This lesson, one from a multi-part unit, challenges students to use a geoboard, geoboard applet, or Geometer’s Sketchpad® to discover the pattern of Pick’s Theorem. Illuminations provides an activity sheet, links to a geoboard applet, and detailed instructions for completing the lesson.
Students will:
- Investigate several geoboard figures to determine the pattern between the number of perimeter pins, the number of interior pins, and the resulting area.
- Create an equation using symbolic algebra to represent the pattern.
NCTM Standards and Expectations:
- Interpret representations of functions of two variables.
- Generalize patterns using explicitly defined and recursively defined functions.
- Make decisions about units and scales that are appropriate for problem situations involving measurement.
North Carolina Curriculum Alignment
Mathematics (2004)
Grades 9–12 — Algebra 1
- Goal 1: Number and Operations - The learner will perform operations with numbers and expressions to solve problems.
- Objective 1.02: Use formulas and algebraic expressions, including iterative and recursive forms, to model and solve problems.
- Goal 4: Algebra - The learner will use relations and functions to solve problems.
- Objective 4.01: Use linear functions or inequalities to model and solve problems; justify results.
- Solve using tables, graphs, and algebraic properties.
- Interpret constants and coefficients in the context of the problem.
- Objective 4.03: Use systems of linear equations or inequalities in two variables to model and solve problems. Solve using tables, graphs, and algebraic properties; justify results.
- Objective 4.01: Use linear functions or inequalities to model and solve problems; justify results.



