1. Enrich Instruction in a Geometry and Measurement Unit with Technology Measuring Around Geometers Sketchpad Classroom iLearn Grade 6 Math Session 2 of 8

2. Focusing Questions How can we use the Geometers Sketchpad to measure around various shapes?

3. Instruction

4. Framing The Session We will continue our exploration of measurement. Why, when, and how do we find perimeter?

5. Teaching Determine the perimeter of the figure below. Ms Chou Mr.Perez Hallway Mrs. Stratton Mr. Perotti Ms Nagel Scale: 1 cm = 2 m What is the perimeter of the hallway? IMPACT Mathematics Course 1 page 482_2 nd ed.,2004 Problem Set A #1

6. Essential Questions What do we know? What do we need to know? What is your estimate of the perimeter?

7. Guided Practice SKETCHPAD EXERCISE Draw 3 points that are not collinear. Use the pointer tool to select the points. From the Construct menu, select draw an arc through 3 points. Use the line tool to draw lines to complete the figure. Use the pointer to adjust the shape of the figure. Highlight the lines and use the Measure menu to measure the length of each line. Impact Mathematics C1 page 485_2 nd ed.,2004 How to construct the figure on C1 page 43_3 rd ed.,2009 (C1 page 485_2 nd ed.,2004) :

8. How do we find the perimeter?

9. How might we estimate the perimeter of the circle?

10. Inscribed Shapes Inscribe a shape in the circle. What is the relationship between the perimeter of the shape and the circumference of the circle?

11. Work Time

12. Circumference Download To A Circle.gsp Notice that as we add more sides to our inscribed shape, the closer it approaches a circle, and the closer the perimeter of the inscribed shape approaches the circumference of the circle. Getting Started

13. Work Time Work in small groups to use Geometers Sketchpad to calculate the perimeter of various polygons. What happens when we add more sides to the inscribed shape? Discuss and display your work from the session.

14. Share

15. Download Circumference.gsp and Circum Diameter.gsp. Circumference

16. What math concepts do these sketches support? Compare and contrast these two sketches. Share

17. What are some benefits to using Geometers SketchPad to teach this math content? What drawbacks and challenges might this software present? Answers

18. For more information Office of Instructional Technology oittc@schools.nyc.gov www.nyc.gov/schools