Study guides

☆☆

Q: What is the formula to find the circumference of a circle when the diameter is known?

Write your answer...

Submit

Still have questions?

Continue Learning about Other Math

Divide the known circumference by pi to find the diameter of the circle.

If you know the diameter and need the circumference you times the diameter of the circle by 3.14 also known as pie. That is how you get the circumference by only knowing the diameter. :)

Multiply the known diameter by the value of PI - and you'll have your answer !

pi = C / d C = pi times d d = C / pi

A circle is a shape with all points the same distance from the center. It is named by the center. The circle to the left is called circle A since the center is at point A. If you measure the distance around a circle and divide it by the distance across the circle through the center, you will always come close to a particular value, depending upon the accuracy of your measurement. This value is approximately 3.14159265358979323846... We use the Greek letter (pronounced Pi) to represent this value. The number goes on forever. However, using computers, has been calculated to over 1 trillion digits past the decimal point.The distance around a circle is called the circumference. The distance across a circle through the center is called the diameter. is the ratio of the circumference of a circle to the diameter. Thus, for any circle, if you divide the circumference by the diameter, you get a value close to . This relationship is expressed in the following formula:where is circumference and is diameter. You can test this formula at home with a round dinner plate. If you measure the circumference and the diameter of the plate and then divide by , your quotient should come close to . Another way to write this formula is: where · means multiply. This second formula is commonly used in problems where the diameter is given and the circumference is not known (see the examples below).The radius of a circle is the distance from the center of a circle to any point on the circle. If you place two radii end-to-end in a circle, you would have the same length as one diameter. Thus, the diameter of a circle is twice as long as the radius. This relationship is expressed in the following formula: , where is the diameter and is the radius.

Related questions

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

The number pi can be defined as: pi = circumference / diameter. Solving for diameter: diameter = circumference / pi. Pi is approximately 3.14.

Use the following formula to figure diameter when the circumference of a circle is known: Circumference = Pi x Diameter 20 = 3.1415927 x D D = 6.366

To find the area of a circle, either the diameter or the circumference must be known. The formula for the area from the diameter is (pi)*(1/2 of diameter) squared. From the circumference, simply substitute (circumference / pi) for diameter.

Divide the known circumference by pi to find the diameter of the circle.

Diameter = circumference/pi where pi is 3.14159 (approx)

The formula to find the circumference of a circle with a known diameter is: Pi (3.1416) times by diameter. Therefore, 3.1416 x 1.75 = 5.4978 (or 5.50 rounded to 2 decimal places).

The Circumference is approximately 143.60. Circumference = 3.14159265 (known as Pi) x Diameter. Cheers!

If you know the diameter and need the circumference you times the diameter of the circle by 3.14 also known as pie. That is how you get the circumference by only knowing the diameter. :)

The length around a circle is the circumference The length across a circle is the diameter

Times it by pi

π was originally known (to the Greeks, I think) as the ratio of the circumference of a circle to its diameter, thus: circumference/diameter = π which with rearranging becomes: circumference = π x diameter However, the diameter of the circle is the distance from one point on its circumference to its centre and then onto another point on the circumference so it is also twice the radius in length, that is: diameter = 2 x radius which can be substituted back into the formula above to yield: circumference = π x 2 x radius or circumference = 2 x π x radius which is usually abbreviated, in algebra, to: circumference = 2πr with r representing the radius of the circle, and π the ratio as previously described.

People also asked