Question

. The ratio of a circumference to diameter is​

Answer 1

One of the most fundamental truths of (Euclidean) geometry is that the ratio of the circumference to the diameter of any circle is a constant, and that constant is called pi (denoted by π π). Let C be the (length of the) circumference of a circle, and let d be its diameter. Then, we must have: C d = π C d = π