Unit 4 - Circle Theorems

Unit Objectives
​Prior Knowledge/For Review – Students should be able to:
  • Find the area and circumference of a circle
  • Find the area and perimeter of a sector
  • Vocabulary of circles: radius, diameter, circumference, sector, arc, semicircle
  • Find missing angles on parallel lines
IGCSE Core Learning Objectives – Students should be able to:
  • Use and interpret the vocabulary of circles
  • Know and use the following properties of circles:
           o    Tangent is perpendicular to radius at the point of contact (Video 4.01)
           o    Tangents from a point are equal (Video 4.02)
           o    Angle in a semicircle is right angle(Video 4.03)

IGCSE Extended Learning  Objectives – Students should be able to:
  • Know and use the following properties of circles: (4.7)
           o    Angle at the centre is twice angle at the circumference (Video 4.04)
           o    Angles at the circumference on the same arc are equal(Video 4.05) 
           o    Opposite angle in cyclic quadrilateral add to 180(Video 4.06)
  • Solve problems involving area, circumference and properties of circles, arcs and sectors (Video 4.07) (Video 4.08) 
Lesson Resources​
0. Circle Theorems Booklets
1. Angles in Semicircles
2. Angle at the Centre vs Angle at the Circumference
3. Angles in the Same Segment
4. Angles in Cyclic Quadrilaterals
5. Tangents
6. Circle Theorems Review
7. ​Sectors of Circles
8. UNIT REVIEW
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