What exactly is r*2 in the formula Pi r*2? Radius squared?

Question

This is confusing for me. I would like to see a visual of what r*2 really is. I have been unsuccessful with my research. Thanks!

I want to SEE a VISUAL PICTURE on how radius squared looks like. PLEASE!

Answer 1

to visualize r squared think of a square with 4 sides that are all r (inches) long

Answer 2

Hi:

Your answer is not correct because of the missing "=" to something , However it could mean 2*r which is the circle's diameter, but the guy or gal that wrote your formula if he or she meant to say radius square: Than he or she should have used the " ^ " symbol instead of the " * " and they might have not rearrange the terms in your formula from r*2 to 2*r or 2r

You decide which one it for?

here are five circle equations for what your talking about above:

D= 2*r

C= 2*r* pi

C= D*pi

A= pi* A^2

A= .25*D^2

C= circumference D= diameter

r= radius A = Area pi approx = 3.14159265358


and to the see the radius squared part; draw a circle and draw two lines from the center one at the zero degree going from the circle's center to it edge, as for the other one : go from the center to the 90 degree mark on the circle edge, a better way to say this; is draw two line 90 degrees apart from the center of the circle to the circle edge.

now extend the lines at 90 degrees from where they hit the edge of the circle when they meet up again they should from a square that is why they the radius are squared due the side of the square are equal the lenght of the radius. and due to Pythagorean theorem on right triangles. Try it and you will see it for yourself. Okay

A very qood question.

Answer 3

r is the radius.. which is a single dimensional measurement. r^2 (not typically written as r*2) is a 2 dimensional measurement, commonly called "area". It should be obvious that the area of a circle is related to its radius squared, since "area" must be "squared", and as the radius gets bigger, so does the size of the circle. The magic is in the PI constant. It's the value that magically relates the radius (and radius squared) to the real area of the circle. The following picture should help you understand at least the r^2 part; it shows that area in gray. It happens to turn out that there are about 3.14 times that much space in a circle. Why is that? That's magic of PI!

http://upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Circle_Area.svg/265px-Circle_Area.svg.png

Answer 4

radius squared

Answer 5

r = Radius. Bingo.

Its pretty hard to describe why unless you want to get into intergration, which I'm guessing you don't

Answer 6

Yes

Ana

Answer 7

the radius. half the diameter..