Information AboutCircle |
| CATEGORIES ABOUT CIRCLE | |
| circles | |
| geometric shapes | |
| curves | |
| conic sections | |
| pi | |
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In Euclidean Geometry , a circle is the Set of all Points in a plane at a fixed Distance , called the ''radius'', from a fixed point, the ''centre''. The points can only be those that are part of a Conic Section ; within the set of a Plane bisecting a Cone . Circles are Simple Closed Curve s, dividing the plane into an interior and exterior. Sometimes the word ''circle'' is used to mean the interior, with the circle itself called the circumference(C). Usually, however, the ''circumference'' means the length of the circle, and the interior of the circle is called a '' Disk ''. An ''arc'' is any continuous portion of a circle. MATHEMATICAL DEFINITIONS ]] area element]] In an ''x''-''y'' Coordinate System , the circle with center (''a'', ''b'') and radius ''r'' is the set of all points (''x'', ''y'') such that : If the circle is centred at the origin (0, 0), then this Formula can be simplified to : The circle centred at the origin with radius 1 is called the Unit Circle . Expressed in Parametric Equations , (''x'', ''y'') can be written as x y The Slope of a circle at a point (''x'', ''y'') can be expressed with the following formula, assuming the centre is at the origin and (''x'', ''y'') is on the circle: : |
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