Bolt-Circle Diameter
Module designer(s)	Ed Malczewski
E-mail address(es)	Ed Malczewski
URL	https://mste.illinois.edu/TCD/Bolt_diameter/problem.html
Cooperating teachers	Joe Sosine
Objectives	Investigate trigonometric ratios Determine the bolt circle diameter of a tire given it's chord length and vice versa Investigate the connection between the circumference of a circle and PI using many sided polygons
Materials	Internet access Geometer's Sketchpad
Related Courses	Geometry Pre-Calculus
Links to standards	National Science Education Standards Science as Inquiry  NCTM Standards: Standard 1: Mathematics as Problem Solving Standard 2: Mathematics as Communication Standard 3: Mathematics as Reasoning Standard 4: Mathematical Connections Standard 9: Geometry and Spatial Sense Standard 13: Patterns and Relationships
Highlights	Using the Geometer's Sketchpad to solve a problem often seen in automotive technology: determining the bolt circle diameter of a tire.