The question can be answered in many ways.
Without knowing the specifics of the question, this is the best answer that can be given at this time.
A hubmeter.
I would use a odometer or a trundle wheel
trundle wheel
Surveyor's Wheel
it measures the length or distance
A cycling odometer uses sensors to measure the rotation of the bike's wheel. It then calculates the distance traveled based on the wheel's circumference and displays this information on a screen.
36 pi
A simple bike odometer typically includes features such as a display screen showing distance traveled, a reset button to clear previous data, and a sensor that tracks wheel rotations. It helps track distance by measuring the number of wheel rotations and converting it into distance traveled, providing cyclists with an accurate measurement of their biking distance.
To accurately track the distance you have traveled on your bicycle using an odometer, you need to first calibrate the odometer by entering the correct wheel size. Then, make sure the odometer is securely attached to your bike and start cycling. The odometer will measure the rotations of your bike's wheel and calculate the distance you have traveled based on the wheel size. Make sure to regularly check and calibrate the odometer to ensure accurate tracking of your distance.
You can use this tool called a trundle wheel. It's a wheel attached to a stick and after you walk a few steps, it tells you how much did you walk. Like if you wanted to find the distance from a dog to a cat you ue the trundle wheel and walk from the dog to the cat while the wheel rolls along the floor at all times and when you stop, the trundle wheel tells you approximately how far did you walk.
oil
wheel diameter times pi times number of rotations