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Enter the radius length and it calculates the area for you. Areaī's Area of a Circle Calculator – Provides the area of a circle formula as a reference. It also features a labeled circle diagram. It will find the circle's diameter, area, and circumference. 's Circle Calculator – This easy-to-use tool prompts you to enter the radius of a circle. It can also be used to for figuring a sphere's surface area and volume. Just enter the radius and it finds the circumference.Ĭ's Circle and Sphere Area Calculator – Enter a known value to find the area, radius, diameter, or circumference. 's Circumference Calculator – There are no bells and whistles here. It also provides the circumference formula. Just enter the radius length and it will provide your result. Circumferenceī's Circumference Calculator – Provides a quick and easy way to find a circle's circumference. It also features tutorial information about circles, needed formulas, and a circle diagram.į's Circle Calculator – Features easy-to-understand definitions of circle area, circumference, diameter, and radius. 's Circle Calculator – Enter your radius and it will find the circumference, area, and diameter. Enter one known value and it will find the unknown values, including the radius, diameter, area, or circumference. 's Circle Calculator – This is quick, easy-to-use, and features a circle diagram with a marked radius and diameter. It also provides easy-to-understand tutorial information and formulas as a reference. 's Find Out Things About Circles – Use the drop down menus to find a circle's radius, diameter, circumference, or area. It includes a diagram to help explain.Įas圜's Circle Calculator – This easy-to-use utility helps you find several aspects of a circle, such as diameter, area, and circumference.ġ728.org's Circle Calculator – When you know two variables (area, volume, radius, height), this will help you find the other two. It includes some tutorial information as well as circle formulas and examples.Įas圜's Radius of a Circle – This tool helps you find the radius of a circle using four known points. Basic Plane Geometry Circles Multiple FunctionsĬ's Circle Calculator – Use the drop down menu to find a circle's area, circumference, or radius. Plane GeometryĪs explains, plane geometry is the study of “flat shapes like lines, circles, and triangles.”īelow is a collection of plane geometry calculators divided by skill level. Below is a collection of 232 calculators separated by type of geometry and skill level. It can be difficult to sift through them all. There are tons of geometry calculators available online. As Khan Academy notes, it is about the “nature of these shapes, how we define them, and what they teach us about the world at large.” Geometry is much more than the study of shapes.
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Pythagorean Theorem and Right Triangles.The polar form looks somewhat similar to the standard form, but it requires the center of the circle to be in polar coordinates from the origin. It is based on the definitions of sine and cosine in a right triangle. This is a variable which can take any value (but of course it should be the same in both equations). This equation is called "parametric" because the angle theta is referred to as a "parameter". The parametric equation of a circle with the center at and radius is From this circle equation, you can easily tell the coordinates of the center and the radius of the circle. You can convert general form to standard form using the technique known as Completing the square. The standard equation of a circle with the center at and radius is But it can easily be converted into standard form, which is much easier to understand. With general form, it is difficult to reason about the circle's properties, namely the center and the radius. The general equation of a circle with the center at and radius is There are different forms of the equation of a circle: That is, if the point satisfies the equation of the circle, it lies on the circle's circumference. An equation of a circle is an algebraic way to define all points that lie on the circumference of the circle.
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