the diameter of a circle is 4 cm. Which equation can be used to find its circumstances?

Answer:
The third answer.
Step-by-step explanation:
There are two formulas for circumference:
[tex]C = 2\pi r[/tex]
[tex]C = d\pi[/tex]
They give the diameter of 4, and they are going to use a combination of both formulas for the answer. They are using the second formula and then they are changing the diameter to a radius by dividing by 2.