Education Technology

Constructing a Pentagon, An Alternative Method

Author
Subject Area
Math: Geometry: Circles
Math: Geometry: Points, Lines and Angles
Math: Geometry: Quadrilaterals and Polygons
Level
9-12
Activity Time
45 Minutes
TI Calculator
TI-Nspire™ CX series
Other Materials
A detailed instruction sheet, with screen shots is included. A TNS file shows the completed pentagon.
Resource Types
Lessons

Constructing a Pentagon, An Alternative Method

Activity Overview

Use the TN-Nspire (OS 2.0) to construct a regular pentagon using lines, rays, line segments, and circles of various diameters. The characteristics of a regular pentagon are discussed and used to verify the construction meets the criteria of all sides being equal, and all angles being equal. The measurement feature of the TI-Nspire is used to verify angle measurements, while circles verify sides are congruent.

Before the Activity

Download and make copies of word document for teacher and/or students to use. It is detailed enough for students to use for self discovery.

A Video is available, but too large to upload to TI website (8MB) It is available at
http://www.teachertube.com/viewVideo.php?video_id=176582

During the Activity

I suggest you use the smaller circle, and line from bottom through left midpoint. Hide to make construction easier and less confusing.

After the Activity

Follow through in verifying all the angles are equal, and all sides are equal. Note: to increase decimals for the angle measurement, place cursor on the number (text) and press "+", to decrease, press "-". Also suggest use the settings for "Graphs & Geometry" to change from radians (default) to degrees. Be sure to change for Geometry Angle.

Author
Subject Area
Math: Geometry: Circles
Math: Geometry: Points, Lines and Angles
Math: Geometry: Quadrilaterals and Polygons
Level
9-12
Activity Time
45 Minutes
TI Calculator
TI-Nspire™ CX series
Other Materials
A detailed instruction sheet, with screen shots is included. A TNS file shows the completed pentagon.
Resource Types
Lessons
iPad is a trademark of Apple Inc., registered in the U.S. and other countries.
Vernier EasyData,Vernier EasyLink and Vernier EasyTemp are registered trademarks of Vernier Science Education.