Generalizations. The definitions given above are only valid for circles, spheres and convex shapes. However, they are special cases of a more general definition that is valid for any kind of n-dimensional convex or non-convex object, such as a hypercube or a set of scattered points. The second formula that you can find the diameter of a circle is: D = circumference divided by PI. The number PI is used in mathematics to denote a particular irrational number, and is approximately 3,14. Diameter of a Circle. Diameter of a Circle. Skip navigation Sign in. Search. Loading. Close. This video is unavailable. Watch Queue Queue. How to find (diameter) of a Circle Construction Technology & civil Work. Loading. Unsubscribe from Construction Technology & civil Work? Calculate the diameter of a circle, from its area. Area (q): Area units: The diameter of a circle is the length of a straight line going from one side of a circle to the opposite side. To measure the diameter, simply choose two points on the edge of a circle that are directly across from each other, and measure the distance between these points. __count__/__total__ YouTube TV - No long term contract How to Calculate the Circumference of a Circle. Whether you're doing craft work, putting fencing around your hot tub, or just solving a math problem for school, knowing how to find the circumference of a circle will come in handy in a. To find the area of a circle, you take pi times the radius squared, or A = pi r^2. Using this formula, you can find the area of a circle if you know the radius -- or the diameter -- by plugging in your values and solving for A. Pi is approximated as 3.14. The diameter of a circle is any line that passes through the center of a circle and has its endpoints on the circle. If you know a circle's radius or circumference, it's easy to find its diameter. How to Calculate the Diameter of a Circle. 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. It's also possible if you don't know any of the above.