Bolt Circle Diameter Module:
Finding the Bolt Circle Diameter from Chord Length

MSTE logo

Partnership Illinois

  Bolt Circle Diameter Lesson
  Contact Information

Lesson Worksheet 1

To do this part of the lesson, download this Geometer's Sketchpad file.

Open the Sketchpad file and follow the following steps.

DATA: 12 cm bolt circle diameter - 5 bolt pattern

The first thing we need to find is the BOLT SPACING which is the number of degrees between each of the lug nuts.

STEP 1: Measure <EAD, <DAC, <CAB , <BAE , <FAE 

What do you notice about each of the lug spacings? 

STEP 2: Add all the angle measures. What do you get?

STEP 3: In a 4 bolt pattern, each of the angle measures was measured as be 90. What is the sum of all the angle measures? 

STEP 4: Make a conclusion about the sum of the lug spacing angles for any numbered bolt pattern.

STEP 5: If there were 6 lug nuts on a tire, what would the lug spacing be?

-Back to Problem Statement-  -Go to Lesson Worksheet 2-