Circumference of A Circle
The perimeter of a circle, often called circumference, is proportional to its diameter. That is to say, there exists a constant number π (the greek p for perimeter) which gives, if P is the circle's perimeter and D its diameter:
- P = π D.
If one knows the radius R of the circle, this formula becomes:
- P = 2 π R.
To calculate a circle's perimeter, the knowledge of its radius or diameter and of the number π is sufficient. The problem is that π is not rational (it cannot be expressed as the quotient of two integers), nor algebraic (it is not a root of a polynomial equation with rational coefficients). So, obtaining an accurate approximation of π is not easy. The search for the digits of π mobilizes many fields, such as mathematical analysis, algorithmics and computer science.
Read more about this topic: Perimeter
Famous quotes containing the words circumference of and/or circle:
“A fact is the end or last issue of spirit. The visible creation is the terminus or the circumference of the invisible world.”
—Ralph Waldo Emerson (1803–1882)
“It is a good lesson—though it may often be a hard one—for a man who has dreamed of literary fame, and of making for himself a rank among the world’s dignitaries by such means, to step aside out of the narrow circle in which his claims are recognized, and to find how utterly devoid of all significance, beyond that circle, is all that he achieves, and all he aims at.”
—Nathaniel Hawthorne (1804–1864)