Circle
Definition : A circle is a set of all points in a plane which are equidistant a fixed point in the plane . A circle is a closed two-dimensional figure in which the set of all the points in the plane is equidistant from a given point called “centre”. Every line that passes through the circle forms the line of reflection symmetry. Also, it has rotational symmetry around the centre for every angle. The circle formula in the plane is given as: (x-h) 2 + (y-k) 2 = r 2 where (x,y) are the coordinate points (h,k) is the coordinate of the centre of a circle and r is the radius of a circle. Circle Shaped Objects There are many objects we have seen in the real world that are circular in shape. Some of the examples are: Ring CD/Disc Bangles Coins Wheels Button Dartboard Hula hoop Parts of Circle Annulus - The region bounded by two concentric circles. It is basically a ring-shaped object. See the figure below. Arc – It is basically the connected curve of a circle. Sector – A region bou