What is the formula, or how do you find the diameter of a circle when only the area of the circle is known?

Question

This is one out of the many questions that are part of my summer math homework except mine actually tells me the area. I tried to figure it out on my own but I didn't get it. >< And when I asked my college friend, he said that there is a formula but he forgot what it is. So, could I ask someone who knows how to at least help with the steps--- for instance, u gotta know the formula which is ______ _____ _____ then....

so I can use that as reference to help solve my problem.
Thank you so much to everyone who helps!

Answer 1

I am so proud of you for doing you summer homework! Would be great if more kids were like you. Check out the website below, I think it will help. Good luck!

Answer 2

If I remember correctly the formula to find the area of a circle is pi times the radius squared.

Divide the area by 3.14 or whatever figure you have for pi, and then take the square root of the number that gives you.

Then multiply that number by two and you have the diameter of the circle.

So that, if the area is 28.26 square units, then divide by pi (3.14) which gives you 9, and the square root of 9 is 3 and 3 is the radius, so 6 would be the diameter.

Answer 3

Your math homework is going to be very difficult if you don't write all you basic formulas down on one sheet of paper. Geometry is nothing but formulas. There are often multiple steps so you don't always get to just plug in numbers. This problem requires two steps. So write this stuff down and add to it every time you get a new formula.

pi = 3.14
(approximately)

the diameter of any circle is twice its radius
D=2R

The area of a circle = 3.14 * radius * radius
(no good way to write pi * radius squared)

So use that area you have to find your radius then use your radius to find your diameter.

So take the area and divide it by 3.14. Then take the squre root of that number. Then multiply that number by 2 and that's your diameter.

Answer 4

A=2 pi r^2. Thus, the radius is equal to the square root of the Area divided by 2 pi. Double that, and you have the diameter. Good luck.

Answer 5

Area of a circle is equal to 2*pi*radius^2
(Two times pi times the radius squared)
Since diameter is equal to twice the radius, first find the radius by setting the area equal to 2*pi*r^2, and then multiply the radius by two to find the diameter.

Answer 6

the area of a circle is equal to pi * r^2

the first thing you need to do is find the radius which is half of the diameter. Just take the diameter and divide it by two.

than just plug the radius into the formula

so you are going to have 3.14 * r * r

hope that helps

Answer 7

Area of circle = pi * radius squared

Say area is 56

First, solve for radius:
56 = 3.14 * radius squared
radius squared = 56/3.14 = 17.83

radius = square root (17.83) = 4.22

Next, Diameter = 2 * radius = 2 * 4.22 = 8.44

Since diameter = 2 * radius
and area = pi * radius squared

diameter = 2 * squareroot(area/pi)

Answer 8

let,
A = area of the circle.

Formula for area of the circle is pi x r x r

therefore,
A = pi r^2

since pi is approximately 3.14159 and the area of the circle is given, you will be able to find r^2 and subsequently, by squareroot, the value if r.

with r found, you can now solve for D = diameter of the circle, or C = circumference of the circle.

D = 2r
C = pi x D
= pi x 2r

hope this helps. :P

Answer 9

section w/ in straight forward words diamter: purely use pi*radius^2 divide the diamter by 2 and use the formula circumference w/ in straight forward words radius or diameter: use 2*pi*radius if u are given the diameter, divide it by 2 and remedy

Answer 10

A = pi r squared if A means Area and pi means 22/7 and r means radius. now if you know the area and you know pi, can you determine the radius?

Answer 11

3.14x radius Squared= area of circle reverse the process (area of circle dived by 3.14 or pi = radius turn radius into diameter radius is half the diameter real simple