## 5. The Centre of a Triangle

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Using a compass and straight edge, we find the four traditional centres of a triangle : i.e. the incentre, the circumcentre, the orthocentre and the centroid.    We also look at the Medial Triangle, and the Euler Line.   The Centre of a Triangle (Compass and Straight Edge) PowerPoint Lesson: Compass and Straight Edge – The […]

## 1. Angles-Introductory Terms

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In this video, Teacher Jon introduces the basic terms students need for the study of Angles. Video Lesson: Download Worksheet (PDF): ANGLES-Introductory Terms

## 2. Easy Angle Problems

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In this lesson, Teacher Jon provides some easy angle problems, for Lower Secondary Maths students, but a basic knowledge of the terms and symbols used in Angles is still required– (for instance, see my video on Angles – Introductory Terms) . Video Lesson: Download Worksheet (PDF): ANGLES – Easy Angles Problems

## 3. The World’s Two Hardest Easy Geometry Problems

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In this video, Teacher Jon sets out how to solve these two well known geometry problems using only isosceles, equilateral and congruent triangles. Video Lesson: Download Worksheet (PDF): World’s Two Hardest Easy Geometry Problems(Geometry-Angles)