2006-08-28 13:10:40 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Geography
The ratio of the Circumferece, C of a Circle to its Diameter D is a very useful constant called PI, found in many fields and nature. PI is an irrational number.
PI = C/D = 3.1415926...
The Diameter of a Circle is given by D = 2 x r, where r is the radius of the Circle.
The Circumference of a Circle, C is given by 2 x PI x r.
The Area of a Circle, A is given by PI x r^2.
The Center of a Circle suspense 360 degrees.
The Angle formed by the two end points of a Diameter to another point on the Circumference is 90 degrees.
The Equation of a Circle is r^2 = x^2 + y^2
Many people asked, "Where is the beginning of a Circle?"
Access to the center of a Circle from the Circumference has the same distance. This is good for Red Blood cell that needs to absorb oxygen and dispense food.
A Circle has no sharp corners, so it is very mobile. Blood cells assume this shape so that it can travel quickly without much obstructions.
It has one of the most useful shapes that a wonderful invention, the Wheel took inspiration from.
Two Circles always touch each other in the same way.
A straight line touching (resting) on a Circle's Circumference forms a tangent.
A Circle starts and ends at the same place.
There are may Circles (or Cycles) of Life and Nature. Water Cycles, Life Cycles, Carbon Dioxide Cycle, Food Cycle, are examples of systems that move in a Circular fashion.
The Earth, Moon, Sun, and other planets, moons, stars assume Circular shapes and many move in roughly circular orbits.
Another equation of a Circle is Sin^2(x) + Cos^2(x) = 1
The Circle is a very useful Basic Shape that can be used to form other shapes such as a Sphere, Circular Cone, Cylinder.
You get maximum Area with Minimum Circumference material with a Circle. Good for Pizza, Hamburgers, Cakes, etc.
The good thing about the Circle is that "What goes around, comes around."
2006-08-28 13:59:59 · answer #1 · answered by ideaquest 7 · 0⤊ 0⤋
They are round and perfectly formed.
The start of the circle joins the end of the circle making it impossible to see where the circle began.
2006-08-28 23:03:50 · answer #2 · answered by ihopetokissafrog 3 · 0⤊ 0⤋
diameter is twice the radius.
circumference is pi times the diameter.
area is pi times radius squared.
they have 360 degrees.
can be bisected in an infinite amount of ways
and you can't draw a perfect one free hand.
2006-08-28 20:17:11 · answer #3 · answered by ~Genie~ 3 · 0⤊ 0⤋
diameter is twice the radius.
circumfrence is pi times the diameter.
area is pi times radius squared.
they have 360 degrees.
can be bisected in an infinite amount of ways.
2006-08-28 20:14:13 · answer #4 · answered by IT Pro 6 · 0⤊ 0⤋
they are round, they equal 360 degrees all the way a round and it is in a group by itself
2006-08-28 20:16:21 · answer #5 · answered by Morgan P 2 · 0⤊ 0⤋
about circle i know circle
2006-08-28 23:49:30 · answer #6 · answered by corrona 3 · 0⤊ 0⤋
they're round.
=]
2006-08-28 20:12:34 · answer #7 · answered by ♥Jessica 3 · 0⤊ 0⤋