**Highlights**

### 1. Introduction

### 2. Medians Of a Triangle

### 3. Altitudes of a Triangle

### 4. Exterior Angle of a Triangle and Its Properties

5. Angle Sum Property of a Triangle

6. Two Special Triangles : Equilateral and Isosceles

7. Sum of the Lengths of Two Sides of a Triangle

8. Right-Angled Triangle and Pythagoras Property

### Exercise

Problem and Solution.