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ERIC Number: EJ853832
Record Type: Journal
Publication Date: 2009
Pages: 10
Abstractor: ERIC
Reference Count: 6
ISSN: ISSN-0045-0685
Using Tool-Making to Contextualise Geometry: The Super-Size Protractor
Sheppard, Ian
Australian Mathematics Teacher, v65 n2 p31-40 2009
Engaging students with real-world activities can be effective in supporting the learning of mathematics, "whenever possible, real-world situations will provide a context for both introducing and applying geometric topics" (NCTM 1989). Tool making is a way to bring real-world mathematics into the classroom and using the tool is a way of taking classroom mathematics into the student's real-world. This article focuses on a student-constructed protractor. The pedagogical discussion is followed by detailed descriptions of the construction steps. These steps together with alternative constructions offer opportunities to explore deeper mathematics. The construction of the protractor requires the use of a range of techniques that provide context for geometry problems involving congruent triangles, properties of equilateral and isosceles triangles and parallel lines. The protractor is a measurement tool used in constructing and measuring angles and is a learning aid for the teaching and learning of trigonometry, similarity and the unit circle. The author describes two activities, Super-size Protractor and Unique Triangles, which provide a shared experience for future class discourse, and outlines the steps involved in the construction of the Super-size Protractor. As each step is presented, the mathematics of the construction and alternative construction procedures is made explicit and justified along with practical considerations. A list of ways in which the protractor maybe used is presented. (Contains 12 figures.)
Australian Association of Mathematics Teachers (AAMT). GPO Box 1729, Adelaide 5001, South Australia. Tel: +61-8-8363-0288; Fax: +61-8-8362-9288; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Location: Australia