Final answer:
The circumference of a circle is directly proportional to its diameter. The relationship between the circumference and diameter can be expressed as C = 3.142857 * d. When the circumference is 44, the diameter is 14.
Step-by-step explanation:
The circumference C of a circle is directly proportional to its diameter d. This means that if we double the diameter, the circumference will also double. To find the relationship between the circumference and diameter, we can set up a proportion using the given values of C and d:
C/d = k
Where k is the constant of proportionality. Substituting the values C = 66 and d = 21, we get:
66/21 = k
k = 3.142857
So the relationship between the circumference and diameter is C = 3.142857 * d.
To find the value of d when C = 44, we can rearrange the equation:
d = C/3.142857
Substituting C = 44, we get:
d = 44/3.142857
d = 14