Question

The radius of a circle is 9. Using π, which equation expresses the ratio of the circumference of the circle to the circle's diameter? Your answer:

C over 9 equals pi
C over 18 equals pi
C space equals space fraction numerator 9 pi over denominator r end fraction
C space equals space fraction numerator r over denominator 18 pi end fraction

Answer 1

The ratio of the circumference of a circle to its diameter is expressed by the equation C = πd, where C represents the circumference and d represents the diameter.

Step-by-step explanation:

The ratio of the circumference of a circle to its diameter is expressed by the equation:

C = πd

Where C represents the circumference and d represents the diameter. In this case, the question states that the radius of the circle is 9, so we can find the diameter by multiplying the radius by 2:

d = 2 * 9 = 18

Plugging this value of d into the equation, we get:

C = π * 18

Simplifying further, the equation becomes:

C = 18π