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The area of a circle is found with the equation: Area = Pi x radius2.
To find the radius, divide the diameter by two. The next step of the equation is to square the radius. Finally, multiply that by 3.14.
Example: Diameter 20
Find the radius: 20 divided by 2 = 10
Square: 10 times 10 = 100
Multiply by 3.14 for the final answer: 314
(Don't forget to include units! If your original diameter was measured in cm, the area will be in cm2.)
if you have the diameter, just multiply by 3.14 (pi) because that's how long around the outside the circle is no matter what. But if you want to find the area...that's different.
C=pi x D
So let's call the diameter d and you have that then then circumference is the constant Pi multiplied by the diameter or Pixd.
There are many approximations to Pi. It is a constant and an irrational number which means it goes on forever without repeating and cannot be written as a fraction. It can, however, be approximated using fractions. Many people use 22/7 but an even better approximation is 355/113. That is is easy to remember by just writing the number 113355 which are the first 3 odd numbers each written twice and split it down the middle. Put the bigger part on top and you have a very good approximation to Pi.
So for example, say the diameter is 113 inches, then the circumference is approximately 355 inches.
The Circumference of a Circle when the diameter is a known, fixed number is Pi or about 3.14 multiplied by the Diameter 3.14 x D
What else can I help you with?
How do you find the diameter of a circle in the terms of pi?
To find the diameter of a circle, you will either need to know the area or its circumference. If you know the area: diameter = 2 x squareroot(area / Pi) If you know the circumference diameter = circumference / Pi
How do you find the diamter of a circle if you know the area?
In order to find the diameter of a circle if you have the area is to rearrange the formula for the area of a circle to put diameter as the unknown, like so: PIE*d = Area of a Circle d = (Area of a Circle) / PIE Therefore if the area of your circle is 40cm, 40/PIE = 12.73cm and that's the diameter.
How do you find the diameter of a circle when you know the circumference?
circumference/pi = diameter
How dou find diameter?
You measure it. If you know the radius (of a circle), you multiply it by 2 to get the diameter. If you know the circumference of a circle, you divide by pi to get the diameter.You measure it. If you know the radius (of a circle), you multiply it by 2 to get the diameter. If you know the circumference of a circle, you divide by pi to get the diameter.You measure it. If you know the radius (of a circle), you multiply it by 2 to get the diameter. If you know the circumference of a circle, you divide by pi to get the diameter.You measure it. If you know the radius (of a circle), you multiply it by 2 to get the diameter. If you know the circumference of a circle, you divide by pi to get the diameter.
What is the mathematical formula for finding the radius of a circle?
To calculate this you will need the diameter of the circle. The formula is: diameter/2*pi If you don't know the diameter you can also use the area of the circle: Sqrt(Area/pi) = radius
How do you find the diameter of a circle in the terms of pi?
To find the diameter of a circle, you will either need to know the area or its circumference. If you know the area: diameter = 2 x squareroot(area / Pi) If you know the circumference diameter = circumference / Pi
How do you find the area of a semi-circle if you know the diameter?
A semicircle is 1/2 of a circle. Find the area with the diameter you are given as if you had a whole circle, then divide that answer by 2 to get the area of the semicircle.
How do you find the diamter of a circle if you know the area?
In order to find the diameter of a circle if you have the area is to rearrange the formula for the area of a circle to put diameter as the unknown, like so: PIE*d = Area of a Circle d = (Area of a Circle) / PIE Therefore if the area of your circle is 40cm, 40/PIE = 12.73cm and that's the diameter.
How do you find the radius and diameter of the circle if you know the area?
Area of Circle = pi (radius)2 So , using this formula we can find the radius and also the diameter. Diameter = 2(radius)
How do you get the diameter of a circle?
That depends on what you know. If you know the radius of the circle, double it to get the diameter. If you know the circumference of the circle, divide it by π to get the diameter. If you know the area of the circle, find its square root and divide the result by π to get the radius then multiply by 2 to get the diameter.
How do you find area if you know the diameter?
radius = diameter/2 area of a circle in square units = pi*radius2
What is the diameter of a circle with an area of 100πmm3?
I do not know about a circle with an area of 100 nmm3.A circle with an area of 100 mm2 has a diameter of 11.28 mm.
How do you find the radius if you do not know the diameter?
You can measure it. Otherwise, you certainly have to know SOMETHING about the circle to calculate the radius, usually the diameter, the circumference, or the area. If you don't know anything at all about a circle, you can't find out the radius, either.
How do you figure the area of a circle if you know the diameter?
The formula for the area of a circle is: area = pi x radius2. The radius is half the diameter.
'How do you find the radius of a circle?
If you have the circumference- You have to divide the circumference by 2*Pi If you know the diameter the radius is simply half the diameter. If you know the area of a circle, the radius can be found using the formula : R = √A/π where: A is the area of the circle and π is Pi, approximately 3.142.
How do you find the diameter of a circle if you know the circumference?
Divide the known circumference by pi to find the diameter of the circle.
What do you multiply to find the area of a circle?
When you know the circle's radius (r): pi X r2 When you know the circle's diameter (d): pi X (d/2)2
