Radius of the circle : Radius is the distance from the center outwards.
With the help of radius we can determine the following terms:
1. Diameter : Diameter is the twice of radius and it is teh staright line that passes through the center. Expression for the diameter is :
2. Circumference: Circumference of the circle or perimeter of the circle is the measurement of the boundary of the circle. It express as:
3. Area of Circle: Area of a circle is the region occupied by the circle in a two-dimensional plane. It express as:
4. Center Angle of the Sector: Central angles are subtended by an arc between those two points, and the arc length is the central angle of a circle of radius one. It express as :
5. Arc length : An arc of a circle is any portion of the circumference of a circle. It express as :
In the given figure the radius is AO & BO