Slide 2: 2x x o This is the ARC Centre of Circle Angle subtended at the Centre is twice the angle at the circumference Case 2
Slide 3: x x x We are ALL EQUAL This is the Arc Angles Subtended in the same segment of a circle are equal Chop Sticks Minor Segment Major Segment
Slide 4: o A B C D x 180- x If this angle was 60 0 then angle BCD would be 180 0 -60 0 =120 0 120 0 Cyclic Quadrilateral Points which lie on the circumference of the same circle are called cyclic (or concyclic) points. A cyclic quadrilateral is a quadrilateral with all its four corners (vertices) on the circumference of the same circle.
Slide 5: Tangents T A B O TA=TB NB Triangles OBT and OAT are CONGRUENT! Tangent Tangent
Slide 6: Major Segment Minor Segment A B C E D The Shaded Segment BED is called the alternate segment to the angle CBD The angle between a tangent to a circle and a chord drawn through the point of contact is equal to any angle subtended by the chord at the circumference in the alternate segment
Slide 7: Centre of Circle Diameter The angle in a semi circle is 90 degrees!