pi*radius2 = area of a circle
radius2 = area/pi
radius = square root of (area/pi)
diameter = 2*radius
By dividing the diameter by 2 will give the circle's radius. Area of any circle = pi*radius squared.
to find the diameter of a circle when you only have the circomference you: divide the circomference by pi (approx. 3.14)
The Perimeter of a circle is it's circumference. And the circumference is the diameter times pi. So to find the area, divide the circumference by pi, and get the diameter. Then divide the diameter by 2, to get the radius. Then multiply the radius times itself, and multiply that by pi.
To find the circumference of a circle, you need only know the radius or diameter of the circle. The circumference of a circle is calculated as 2 x Pi x radius OR Pi x diameter. Pi is approximately 3.1415926.
Area = Pi(radius)squared. You only need the radius of a circle to find the area. To find the radius, when you have the diameter, divide the diameter by 2, because the diameter forms two radii. After you have found the radius, plug in the radius into the area equation: Area = Pi(radius)squared In other words, you can say the other equation for the area of a circle is: Area = Pi(1/2Diameter)squared
If you have only the arc length then you cannot find the diameter.
Pi x diameter
If Area of a circle = 2 * pi * rAnd Diameter = 2 * rTherefore:Diameter = 2 * r= Area of circle / piwhere pi = 3.14
Divide the diameter by 2 giving the radius, multiply it by itself (square it), multiply by 3.1416 (called pi).
Circumference of a circle: pi times diameter
The circle must have a diameter, so maybe your teacher just didn't tell you the diameter. In order to figure out the question, you need to know some information about the circle. Weather it's the radius, circumference, or diameter. So here's how you find area if you only have each of the three: 1. If you just have the radius, then square the radius. This means multiply radius times radius. Or say the radius is 4. Squaring it is 4 times 4. So once you find out the answer for radius squared, multiply radius squared by pi. (Probably use 3.14 for pi) Then there's your area. 2. If you only have the circumference of a circle, then you need to find the radius. In order to do that, you need to find the diameter. To find the diameter of a circle, you take the circumference and divide it by pi. (3.14) then you have your diameter. Since the radius is half the diameter, divide the diameter by 2. Then, once you find the radius, you may look at step 1 and use those steps to find out the area. Since your question is wondering how to find the area without knowing the diameter, then you can multiply the radius by 2 to find out the diameter. Even though you don't need to know the diameter to find the area. You just do (r times r) times pi (3.14)
Find the area of the circle and divide by 4.