Customizable Inscribed Angle Geometry Manipulative

thingiverse

This is a fully customizable 6" diameter geometry manipulative that helps teach and learn about properties of angles, inscribed angles, central angles, arc lengths, and arc measures. Use with a rubber band or two to discover the relationship between inscribed and central angles. Equally spaced holes for small nails are around the circumference along with one in the center. An STL file of a 6" disk that printed well is also included if you don't want to mess with the customizer. If planning on using this to complement lessons on the subject, print a classroom set so each student can explore, or at least print enough so that each table group can share one. Additional materials needed are rubber bands, small nails (I used some 5/8" nails I had in my workshop with 0.8mm holes) to tap into holes, and a hammer. If you like this, check out my other objects, including the non-customizable version of this manipulative at: http://www.thingiverse.com/thing:2179477. Also, if you want a modification to this design, let me know in the comments and I'll see what I can do. Updated 3/19/17 - A new version was modeled in Inventor (see the Version 4 STL file, not added to Customizer file yet) that has 24 central angles (15 degrees each) around the whole circle, along with 12 inscribed angles radiating 180 degrees from a single point on the circumference (7.5 degrees each). The intent is to better show the relationship between central angles and inscribed angles. Standards CCSS Overview and Background This manipulative helps teach Geometry students about inscribed/central angles, arc lengths/measures, sector areas, and more. It's a resource that teaches to the following Common Core standard: CCSS.MATH.CONTENT.HSG.C.A.2 - Identify and describe relationships among inscribed angles, radii, and chords. Lesson Plan and Activity Pass out these inscribed angle manipulatives after teaching students about the relationships between inscribed and central angles. Allow students to explore relationships between radii, arc measure, and angles. Materials Needed One manipulative per person or table group To assemble each manipulative you will need: -one printed disk -enough nails to fill all the holes - short nails are preferred with diameter approximately the same as hole diameter, tight fit good to keep nails secure. -several rubber bands.