Important properties of Circle | Basic of Circle | Chord of Circle | Arc of Circle | Radius of circle | Diameter of Circle | minor circle | major circle |

Important properties of Circle:- 

◆ A circle lie on when plane divide into three parts, which are :-
1. Inner part of circle i.e. interior 
2. Circle i.e. circumference 
3. Outer part of circle i.e. exterior

◆  if chords of any circle subtends equal angles at the centre, then chords are equal. 
◆ Equal chords of a circle subtends equal angles at centre.
◆ if two arcs of any circle are congruent, then their corresponding chords are equal. 
◆ if two chords of a circle are equal, then corresponding arcs are congruent.
◆ The perpendicular from the centre of a circle to a chord bisects the chord.
◆  the line segment joining the centre of a circle to the midpoint of a chord is perpendicular to the chord. 
◆ There is one and only one circle passing through three given points.
◆ Equal chords of a circle are equidistant from the centre.
◆ Chords of a circle which are equidistant from the centre.
◆ The angle subtended by an arc of a circle at the centre is double the angle subtended by it at any point on the remaining part of the circle.
◆ The angle in a semicircle is right angle.
◆ If arc of any circle subtended a right angle at any point in its alternate segment , then this arc or alternate is semicircle. 
◆ Taking hypotenuse of right angled triangle as diameter , circle drawn passes through the opposite vertex of hypotenuse.
◆ Angle in same segment of a circle are equal.
◆  If a line segment joining two points subtends equal angles at two other points lying on the same side of the segment , the four points are con cyclic i.e. lie on the same circle. 
◆. sum of opposite angle of a cyclic quadrilateral is 180° or two right angles.
◆. If one pair of opposite angles of any quadrilateral is supplementary , then it is cyclic quadrilateral.