This activity begins an exploration of geometric shapes by asking students why the five-sided (pentagonal) water control valve of a fire hydrant cannot be opened by a common household wrench. The activity, part of the Figure This! collection of 80 math challenges emphasizing math in the real world, explains how geometric shape contributes to the usefulness of many objects. A hint on the page calls students' attention to the shape of a normal household wrench, which has two parallel sides. Related questions ask students to think about the shapes of household bolts and to compare the usefulness of a regular hexagonal bolt to a bolt that has sides of unequal length. Answers to questions and links to resources are included. Copyright 2005 Eisenhower National Clearinghouse


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Informal Education,Process skills,Middle School,NSDL,oai:nsdl.org:2200/20120114184119844T,Grade 8,NSDL_SetSpec_1007936,Plane geometry,Geometry,Grade 6,Problem solving,Mathematics,Education,Polygons,Grade 7



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