• thomas576
In summary, circles are a set of points on a plane that are equidistant from a central point. They are defined by their radius, which is the distance from the center to any point on the circle's circumference. The radius is half the diameter of the circle, and it can be found using the formula r = d/2. Understanding circles and their properties, such as circumference and area, can be useful in various fields of study, such as geometry, physics, and engineering.
thomas576
circles... and pie

ok so i found this site and I am learning about circles now :) http://www.mathgoodies.com/lessons/vol2/circumference.html

it says pie is 3.14 which is what you get when you divide the outer measurement of the circle by the diameter (pie being 3.14 as per his homework)

in this problem i have used & to mean pie because i don't know how to make that symbol
circumference of a circle is 6&

so

6&/d=&

6(3.14)/d=3.14
18.84/d=3.14
18.84=3.14d
18.84/3.14=d
6=d
diameter is 2x radius so raidus is 3

sound right?
thanks again guys and gals!

Its right.

You couldve saved some time by dividing both sides by pi in the first step

Just for reference, it is written pi. You can get the pi symbol by using LaTeX code. You write tex or itex in brackets and close them with /tex or /itex in brackets. Write \pi inbetween the code to get the symbol to show up.

Like this: $$\pi$$, click the symbol to see the code to write it.

thomas576 said:
in this problem i have used & to mean pie because i don't know how to make that symbol circumference of a circle is 6&

I like pie However, I believe you are referring to the mathematical constant which whozum correctly spelled pi ..

If you want to make the symbol $$\pi$$ click on the one I made and a popup window will show the syntax you can use, to create it)

(while I was writing this, i see Candyman has a similar suggestion, I wonder if he/she also likes pie )

mmmmm...pie...

FredGarvin said:
mmmmm...pie...
You are too late, Fred. I sneaked up on it all unnoticed yesterday.
You're welcome to the left-overs, however

Last edited:

## 1. What is a circle?

A circle is a two-dimensional shape that is formed by a curved line that is equidistant from a central point, known as the center. It has no corners or straight edges.

## 2. How do you find the radius of a circle?

The radius of a circle is the distance from the center of the circle to any point on the circumference (outer edge) of the circle. It can be found by dividing the diameter of the circle by 2. Alternatively, it can be found by using the formula r = C/2π, where C is the circumference of the circle.

## 3. What is the relationship between the radius and diameter of a circle?

The radius and diameter of a circle are related by the formula d = 2r, where d is the diameter and r is the radius. This means that the diameter is always twice the length of the radius.

## 4. How does the radius affect the area and circumference of a circle?

The radius directly affects both the area and circumference of a circle. The area of a circle is calculated using the formula A = πr², which means that as the radius increases, the area also increases. The circumference of a circle is calculated using the formula C = 2πr, which means that as the radius increases, the circumference also increases.

## 5. Can the radius of a circle be negative?

No, the radius of a circle cannot be negative. It represents a distance and therefore must be a positive value. However, if you are using a coordinate system, the center of the circle can have negative coordinates, but the radius will always be a positive value.

Replies
7
Views
610
Replies
3
Views
14K
Replies
5
Views
1K
Replies
11
Views
3K
Replies
7
Views
4K
Replies
3
Views
1K
Replies
17
Views
12K
Replies
4
Views
3K
Replies
7
Views
3K
Replies
5
Views
2K