Problem Description

In this module students will,

• investigate trigonmetric ratios
• determine the bolt circle diameter of a wheel given it's chord length and vice versa
• investigate the connection between the circumference of a circle and PI using many sided polygons

The above diagram shows a typical bolt pattern consisting of 5 lug nuts. A lug nut is demonstrated by each of the small circles that is around the bigger circle. Once either the chord length or the bolt circle diameter is known, the other can be found.

To find either measurement, it is necessary to use trigonometery. Trigonemetery is the study of triangles and their properties so the first part of this lesson will be to learn a little about triangle ratios and their part in this problem.

If needed a short tutorial is provided if the student is unfamiliar with Geometer's Sketchpad.

GSP - Tutorial.

Otherwise, Continue the lesson.