Bell Work Title Tangent Theorems Date Lesson Sequence

Bell Work Title: Tangent Theorems Date:

Lesson Sequence Lesson 1 Chord Bisector Theorem 2 Tangent Theorems 3 Semi-Circles & Subtended Angles 4 Segments & Cyclic Quadrilaterals 5 Alternate Segment Theorem 6 Circle Theorems Round Up 7 Proof of Circle Theorems 1 8 Proof of Circle Theorems 2 9 Assessment Specification – GCSE Edexcel Maths Teaching from Sept 2015 onwards Spec Reference G 10 Topic GCSE Circle Theorems Lesson Tangent Theorems Sequence 2 of 9 Key Words; Tangent, radius, centre, equal, angle, length.

Lesson Objectives Lesson 2 Competency (Level 1 -3) Proficiency (Level 4 -6) To discover the To consider the relationship between lengths of tangents a tangent and radius. touching circles. Mastery (Level 7 -9) To be able to find missing angles in problems involving tangents.

Circle Theorem 2 The angle between a tangent and a radius is 90 o. o

Circle Theorem 3 From any point outside a circle, only two tangents can be drawn and they are equal in R length. P Q Q T P R U T PT = PQ U

The diagram shows circle, centre O. Work out the missing angle x. P 40° B x A O

The diagram shows circle, centre O. Work out the missing angles x and y. P B 20° x A y O

The diagram shows circle, centre O. Work out the missing angle x. P x A 142° O

The diagram shows circle, centre O. Work out the missing angles x and y. 36° A y B x O

The diagram shows circle, centre O. Work out the missing angles x and z. P 50° A z x B O

GCSE Question

How do you feel about today’s lesson: Write a tweet of what you have learnt today using the key words in no more than 140 characters…