Answer:
Step-by-step explanation:
This problem is on the mensuration of flat shapes, a circle.
The length of the string corresponds to the circumference of the circle.
The lenght of the string can be calculated by using the expression for circumference, if after using the ruler to obtain the diameter "d"
upon measuring the diameter we can further obtain the radius "r"
The expression for the radius is r=d/2 (the radius is half the diameter)
C=2πr
where pi= 3.124 a constant term
Hence Circumference is the same as the length of the string