Question

Which statement is true about the relationship between the diameter and circumference of a circle?

A. The circumference of a circle is always two times the diameter of the circle.

B. There is an exponential relationship between the diameter and circumference of a circle.

C. The constant of proportionality between the diameter and circumference of a circle is pi.

D. The unit rate between the diameter and the circumference of a circle is a rational number.

Answer 1

C. The constant of proportionality between the diameter and circumference of a circle is pi.

Explanation:

The constant pi comes from the relationship between the diameter and circumference of a circle.

Constant of Proportionality

A constant of proportionality is a number that describes the ratio between 2 values. No matter the measurements of a circle, the constant of proportionality between a circumference and diameter is always the same. This means that the circumference divided by the diameter ≈ 3.14.

Pi

Pi is an irrational number that can be estimated but never completely solved. The value of pi can be used to complete many different calculations such as the area of a circle, and it is used in many different functions like sin. For this reason, pi is one of the most important constants in math.