Best Answer

Dear confused (not in a rude way, u do seem confused),Circumference=2xPIxR..............is the best way.For example,If the R (radius) is 20m and PI is 3.14 then you times PI 2 times which is 2xPI (3.14)=6.28, THEN YOU times 6.28 by the R (radius)=125.6m rounded to 1 decimal place will leave you with 125.7m and that will be the circumference.With all the best,

Fatima

The above equation |2×Pi×r = circumference| is correct.

The explanation however, is misleading- primarily the two words written IN CAPS. "THEN YOU"

If everything in a formula, or on one side of an equation is being added, subtracted or multiplied, you are free to solve in any order you choose. This rule does NOT apply to division.

The communative property for multiplicationstates that for any numbers a and b, the following is always true:

(a×b) == (b×a)The associative property for multiplication states that for any numbers a , b, and c , the following is always true:

(a×b)×c == a×(b×c)given that the above are true, the following are also true of our equation...2 × Pi × r 2 × (r × Pi)using the same example from above, you're given a circle with a radius = 20m.

(2 × 3.14) × 20 == 2 × (3.14 × 20)plug in Pi(3.14) and r(20) and then choose the order in which you wish to multiply. Think of the commutative property as what it is. The freedom to commute through the steps in any order.

(2 × 3.14) = (6.28)×20 = 125.6mis the same as... (using the associativeproperty)

(3.14 × 20) = (62.8)×2 = 125.6mis the same as... (using the commutative property)

(20 × 3.14) = (62.8)×20 = 125.6mis the same as... oh I dunno... (still using the commutative property)

(2 × 20) = (40)×3.14 = 125.6mLooking carefully at the order of the last formula, we actually formed a 'new' equation...

Multiplying (2 × radius(20)),

(2_×_20)gave us the diameter(40), which we then multiplied by Pi

(40)×3.14to get the circumference(125.6m).

= 125.6m

If you have the diameter, don't waste your time with 2*r*Pi. Use the equation

d×Pi = circumferenceQ: How do you find the circumference of a circle Is it PIE times diameter times 2?

Write your answer...

Submit

Still have questions?

Continue Learning about Math & Arithmetic

The circumference of a circle is the diameter times pi (3.14)

The circumference of a circle is equal to its diameter times pi. This is also equal to two times its radius times pi.

A circle's circumference equals PI times the circle's diameter. So, to find the circumference of a circle with a diameter of 56 we do the following:3.14159x 56___________________________175.92919YOUR ANSWER IS 176 (rounded)

Circumference of a circle: pi times diameter

The perimeter or circumference of a circle = diameter times pi

Related questions

to find the circumference of any circle, times the diameter(d) by pi and you will get the answers.

The circumference of a circle is the diameter times pi (3.14)

The ratio of a circle's circumference to its diameter is Pi, which is 3.14159. Hence, multiply the diameter by Pi to find a circle's circumference, or divide a circumference by Pi to find its diameter. 8 times pi = 25.13274123.

The circumference of a circle is equal to its diameter times pi. This is also equal to two times its radius times pi.

To find the circumference of a circle you multiply the diameter by pi (3.14), the diameter is two times the radius.

A circle's circumference equals PI times the circle's diameter. So, to find the circumference of a circle with a diameter of 56 we do the following:3.14159x 56___________________________175.92919YOUR ANSWER IS 176 (rounded)

Circumference of a circle: pi times diameter

By multiplying the diameter by pi, since the circumference of a circle is 3.14 times the diameter.

The perimeter or circumference of a circle = diameter times pi

Diameter of a circle = circumference/pi

multiply the diameter times pi (3.14159265)

Multiply the diameter times pi. (3.14159)