Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Circles

9-12

30 Minutes

• ##### Device
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition

TI Connect™

• ##### Accessories

TI Connectivity Cable

## Inscribed Angles Intercepting The Same Arc

#### Activity Overview

Students investigate the properties of angles inscribed in a circle. They use the drawing and measurement tools of Cabri™ Jr. to draw and measure certain angles, and establish the relationship between angles that intercept the same arc. NCTM Geometry Standard covered: Analyze characteristics and properties of 2- and 3-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

#### Before the Activity

• Install the Cabri Jr. App on the students' graphing calculators using TI Connect™, a TI Connectivity Cable, and the Unit-to-Unit Link Cable
• Set up the TI-Navigator™ system
• See the attached PDF file for detailed instructions for this activity
• Print pages 41-43 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to your class.

• Draw a circle
• Mark two points on the circle to determine an arc
• Draw segments that will form the sides of the inscribed angles
• Mark two points to be the vertices of inscribed angles
• Observe the relationship between the inscribed angles
• Explore other inscribed angle pairs by changing length of arc and vertices

TI-Navigator activity:
• Use Screen Capture to check students' progress

#### After the Activity

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary