Determine whether the relationship between the circumfrance of a circle and its diameter is a direct variation. if so, identify the constant of proportionality. justify your response.

The relationship between the circumference of a circle and its diameter represent  a direct variation and the constant of proportionality is equal to the constant

Step-by-step explanation:

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form

where K is the constant of proportionality

In this problem we know that

The circumference of a circle is equal to

therefore

the relationship between the circumference of a circle and its diameter is a direct variation and the constant of proportionality is equal to the constant