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CHAPTER AT A GLANCE
I'm Up and Down, and Round and Round (Circles)
•Unit: Geometry
•Board weightage: Geometry carries about 15 marks out of 80 in Class 9; circles usually give theorem-based and numerical questions (please check the latest sample paper)
•Theorems in this textbook: Theorems 1 to 12 (unique circle through three points, equal chords and equal angles, perpendicular from the centre bisects the chord, equal chords are equidistant, angle subtended by an arc, concyclic points, cyclic quadrilateral)
•Proofs asked: Theorem 2, 3, 4, 5, 6, 9 and 11 are the favourite ones for 3-mark and 4-mark proofs
•Time to revise: about 75 minutes
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