1. Circle Geometry

2. Definitions secant radius diameter centre chord tangent
concentric circles

3. Definitions secant radius diameter centre chord tangent
concentric circles

4. Definitions
minor arc
major arc

5. Definitions
minor sector
major sector

6. Definitions
major segment
minor segment

7. Definitions minor sector minor arc major arc major sector
major segment
minor segment

8. Theorem 1 Equal chords subtend equal angles at the centre
Proof :

9. Theorem 1 Equal chords subtend equal angles at the centre
Proof :

10. Theorem 1 Equal chords subtend equal angles at the centre
Proof :

11. Theorem 1 Equal chords subtend equal angles at the centre
Proof :

12. Theorem 2
If the angles subtended at the centre of a circle are equal, then the chords are equal in length. (Converse of Theorem 1)
Proof :
Your turn

13. Theorem 2
If the angles subtended at the centre of a circle are equal, then the chords are equal in length. (Converse of Theorem 1)
Proof :

14. Theorem 3 Equal chords are equidistant from the centre.
Proof :

15. Theorem 3 Equal chords are equidistant from the centre.
Proof :

16. Theorem 3 Equal chords are equidistant from the centre.
Proof :

17. Theorem 3 Equal chords are equidistant from the centre.
Proof :

18. Theorem 4
The line from the centre of a circle to a chord bisects the chord.
Proof :

19. Theorem 4
The line from the centre of a circle which bisects the chord, is perpendicular to it.
Proof :

20. Theorem 4
The line from the centre of a circle which bisects the chord, is perpendicular to it.
Proof :

21. Theorem 4
The line from the centre of a circle which bisects the chord, is perpendicular to it.
Proof :

22. Theorem 5
The perpendicular from the centre of a circle to a chord bisects the chord.
Proof :
Your turn

23. Theorem 5
The perpendicular from the centre of a circle to a chord bisects the chord.
Proof :

24. Theorem 5
The perpendicular from the centre of a circle to a chord bisects the chord.
Proof :

25. Theorem 5
The perpendicular from the centre of a circle to a chord bisects the chord.
Proof :