Answer: Designing things with round parts may require you to know how to calculate a circumference.
Step-by-step explanation:
The curves on a running or race track are halves of a circle. In order for the track to be fair, the curves and lanes have to be laid out properly. The diameter determines the length of the curve, and then the straight-a-ways can be measured at the correct length to get the exact distance needed for the race. The outer lanes are longer than the inner lanes, so the starting lines are adjusted to compensate for that.
The circumference of a tire on a car has to be figured in to the way the odometer counts the milage and how the speedometer displays the vehicle's speed. The engineers who design the vehicle specify a certain size tire with a known diameter and circumference that matched the calibrations of the speedometer. If someone puts a much larger tire on the vehicle, the circumference will be larger, and the revolutions will result in a longer distance traveled and a higher rate of speed than the instruments on the dashboard are showing. If the circumference is 10% larger, and the driver thinks he is doing 73 mph but he is actually doing 80, he could be surprised when the state trooper pulls him over for 10 mph over the 70 mph speed limit.
