The perimeter of a circle
They are circumferences
An arc
It is the planet's diameter multiplied by pi
The answers depend on what you want to "do" and what information you have.
They are its circumferences
Abdominal fat, often known as "android fat distribution" is often associated with high blood lipids (fats), increased risk for insulin resistance, type 2 diabetes, and high cholesterol levels. Women should have waist circumferences of no more than 35 inches, men, of less than 40 inches.
d = 9.55 cm
Only one.
First you times 3.14 by the diameter and there you go
The ratio of all lengths is the same. The ratio of the circumferences = ratio of the radii = 2:3
For the bust-waist-hip measurements you take the body circumferences (in inch) at the fullest point of the bust, then the thinnest point of the waist and again the fullest point of the hips.