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

Enrich Instruction in a Geometry and Measurement Unit with Technology

Measuring Around Geometer’s Sketchpad Classroom

iLearn Grade 6

Math Session 2 of 8

Focusing Questions

How can we use the Geometer’s Sketchpad to measure around various shapes?

Instruction

Framing The Session

We will continue our exploration of measurement.

Why, when, and how do we find perimeter?

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_2nd ed.,2004 Problem Set A #1

Essential Questions

What do we know?

What do we need to know?

What is your estimate of the perimeter?

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_2nd ed.,2004

How to construct the figure on C1 page 43_3rd ed.,2009 (C1 page 485_2nd ed.,2004) :

How do we find the perimeter?

How might we estimate the perimeter of the circle?

Inscribed Shapes

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

Work Time

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

Work Time

Work in small groups to use Geometer’s 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.

Share

Download “Circumference.gsp” and “Circum Diameter.gsp”.

Circumference

What math concepts do these sketches support?

Compare and contrast these two sketches.

Share

What are some benefits to using Geometer’s SketchPad to teach this math content?

What drawbacks and challenges might this software present?

Answers

For more information

Office of Instructional Technology

oittc@schools.nyc.gov

www.nyc.gov/schools