20A Core skills 1. Copy and complete the table by matching the term with its definition. Term
Definition (i) (ii) (iii)
Chord Sector Circle
(iv) Radius (v)
(vi) Arc Diameter
A A line segment joining the centre to a point on a circle B A line segment joining two points on a circle C A special chord which passes through a centre D A part of the circumference of a circle
E A two-dimensional shape enclosed by an arc and the two radii to its endpoints F A sector whose arc endpoints are the endpoints of a diameter
(vii) Semicircle G A two-dimensional shape made by drawing a curve that is always the same distance from a centre point
2. Find the value of x in each diagram, where O is the circle's centre. Give a reason for your answer in each case.
(i) x° 48° O 124° O x° x°
3. Find the value of x in each of the following. Give a reason for your answer in each case. (i)
(ii) 40° O x° 29° O x° O (iii) x° O 81° (ii) (iii)
4. Find the value of x in each of the following. Give a reason for your answer in each case. (i)
(ii) x° O 32°
5. A, B, C,D and E are points on a circle. |∠BDE| = 108°
Find: (i)
(ii) 336 B
|∠BAE| |∠BCE|
Give a reason for your answer in each case. Linking Thinking 2 C O