How Do You Find Diameter if You Know Circumference

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Calculating a circle's diameter is easy if you know any of the other dimensions of the circle: the radius, the circumference, or the area. Information technology's also possible if you don't know any of the above dimensions but you do have a drawing of the circle. If you desire to know how to calculate the diameter of a circle, just follow these steps.

Calculation Help

1. i

   If you know the radius of the circle, double it to become the diameter. The radius is the distance from the center of the circle to its edge.^[1]

   Instance
   If the radius of the circle is 4 cm, so the diameter of the circle is 4 cm x 2, or 8 cm.

2. ii

   If you know the circumference of the circle, divide it by π to get the bore.

   π is equal to approximately three.14

   but you should apply your calculator to get the most authentic results.^[2]

   Example
   If the circumference of the circle is 10 cm, then the diameter is 10 cm/π, or 3.18 cm.

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3. 3

   If you know the area of the circle, divide the result past π and notice its square root to get the radius; then multiply by 2 to get the diameter. This goes dorsum to manipulating the formula for finding the area of a circle, A = πr², to get the diameter. You can transform this into r = √(A/π) cm.^[three]

   Example
   If the area of the circle is 25 cm², divide that by π and find the square root.
   This equals cm ii.82cm, so the diameter of the circle is 2.82 x 2 = 5.64cm.

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1. 1

   Draw a horizontal line within the circle from one edge to the other. Use a ruler or a directly border to do this.

   It tin can exist at the pinnacle, near the lesser, or anywhere in between.

2. ii

   Label the points where the line crosses the circle points "A" and "B."

3. iii

   Draw two overlapping circles, one using A equally the center and the other using B as the eye. Be sure the two circles overlap similar a Venn diagram.

4. 4

   Describe a vertical line through the 2 points at which the outer circles intersect. This line marks the bore of the circle4.

5. 5

   Measure the diameter.

   Measure information technology using a ruler,

   or for greater accuracy, a pair of digital calipers. You lot're done!

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Add New Question

• Question

  What is diference between radius and diameter?

  

  The radius is one-half the bore.

• Question

  If I have the circumference, how can I calculate diameter?

  

  Divide the circumference past pi.

• Question

  The radius of a dinner plate is half dozen cm; what is the diameter?

  

  Since the radius is half the diameter, to get the diameter, yous'd multiply the 6 cm by two. The diameter of this circular dinner plate is 12 cm.

• Question

  What is the area of a circle?

  

  The area of a circumvolve is surface area=πr2, or pi * the radius squared, make sure to first foursquare the radius so multiply that by pi.

• Question

  How do I trace a circle with a bore of four cm?

  

  You have a couple options. Detect something that is 4 cm in diameter (or slightly smaller) and describe effectually it. Use a compass set to a radius of 2 cm. Use a drawing programme and set the circumvolve properties so that it has a diameter of four cm. Finally, use metric graph paper and plot the graph of x2 + y2 = 4. (1 unit = ane cm).

• Question

  How do I find the area of a circle that has a perimeter of 36 cm?

  

  Carve up the circumference (perimeter) by pi. That gives you the bore. One-half of that is the radius. To become the surface area, foursquare the radius, and so multiply by pi.

• Question

  How exercise I calculate the circumference of a circle to the diameter?

  

  Danoyachtcapt

  Summit Answerer

  C = 3.xiv 10 d

• Question

  What is the diameter of a ball with a book of 288?

  

  The diameter is equal to the cube root of the following: six times the volume divided by pi.

• Question

  How can I notice the coordinates of a diameter?

  

  The diameter is formed from the eye of 1 side of a circle to the other, meaning that at that place are no coordinates since the bore is ever located in the center of the circle.

• Question

  If my radius is 20ft, how can I find the diameter?

  

  Double the radius.

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• Using geometrical formulas and equations gets easier with practice. Ask for help from someone who has worked with circles or whatever other geometrical figures. You're probable to find that questions of geometry will seem less challenging with a little experience.

• Familiarize yourself with the utilise of a compass (the cartoon tool, not the direction-finder). This is a very useful instrument in many applications, including drawing a circle'south diameter, equally outlined to a higher place. A divider (an musical instrument similar to a compass) tin can sometimes exist used in such cases.^[iv]

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Things Y'all'll Need

• Calculator
• Pencil with an eraser
• Compass
• Ruler
• Digital calipers(optional)

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Commodity Summary X

To calculate the bore of a circle, multiply the radius by 2. If y'all don't accept the radius, divide the circumference of the circumvolve by π to get the diameter. If yous don't accept the radius or the circumference, divide the area of the circle past π and so notice that number'southward foursquare root to go the radius. Then, you lot tin simply multiply the radius by 2 to find the circle'south bore. Read the article to acquire how to summate the bore of a circle using a ruler!

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Source: https://www.wikihow.com/Calculate-the-Diameter-of-a-Circle

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