Chapter 10 Circles Notes for Class 9th Maths


Chapter 10 Circles

  • Circles and its Related Terms : A Review
  • Angle Subtended by a Chord at a Point
  • Perpendicular from the Centre to a Chord
  • Circle through Three Points
  • Equal Chords and their Distances from the Centre
  • Angle Subtended by an Arc of a Circle
  • Cyclic Quadrilaterals
  • Circle- circle is locus of such points which are at equidistant from a fixed point in a plane.
  • Concentric circle- Circle having same centre called concentric circle.
  • Two arc of a circle called congruent if they have the same degree measure.
  • If two arc equal then their corresponding chords are equal.
  • The perpendicular from centre to chord of circle, it bisects the chord and converse.
  • There is one and only one circle passing through three non-collinear points.
  • Equal chords of circle are equidistant from centre.
  • The angle subtend by an arc at the centre of circle is twice the angle which subtend at remaining part of circumference.
  • Any two angles in the same segment of the circle are equal.
  • Angle of semicircle is right angle.
  • Equal chords of circle subtend equals angle at the centre of circle.
  • If the all vertices of a quadrilateral lie on the circumference of circle, then quadrilateral called cyclic.
  • In a cycle quadrilateral the sum of opposite angles is 180o and converse.
  • The exterior angle of a cycle quadrilateral is equal to the opposite interior angle.


Please enter your comment!
Please enter your name here