2 2x o Centre of Circle x This is the ARC The Angle x subtended at the centre of a circle by an arc is twice the size of the angle on the circumference subtended by the same arc.
3 Case 2 Centre of Circle x o 2x This is the ARC Angle subtended at the Centre is twice the angle at the circumference
4 Angles Subtended in the same segment We are ALL EQUALxMajor SegmentChop SticksMinor SegmentThis is the ArcAngles Subtended in the same segmentof a circle are equal
5 Cyclic Quadrilateral A If this angle was 600 then angle BCD would be =1200Box180-xDC1200Points which lie on the circumference of thesame circle are called cyclic (or concyclic)points. A cyclic quadrilateral is a quadrilateralwith all its four corners (vertices) on thecircumference of the same circle.Cyclic Quadrilateral
6 BTangentOTATA=TBTangentsNB TrianglesOBT and OATare CONGRUENT!
7 EMajor SegmentDMinor SegmentABCThe Shaded Segment BED is called the alternate segment to the angle CBDThe angle between a tangent to a circle and a chord drawn through the pointof contact is equal to any angle subtended by the chord at the circumference inthe alternate segment
8 The angle in a semi circle is 90 degrees! Center of CircleDiameter