The radius of a circle is 10. Using π, which equation expresses the ratio of the circumference of the circle to the circle's diameter?

please help me

2 answers

circumference = 2πr = 2π(10) = 20π

C : r = 20π : 10
= 2π : 1

Actually, the basic definition of π is Circumference : radius.
= 2πr : r
= 2π : 1
the definition of pi is the ratio circumference:diameter