Geometry is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. Mensuration is the part of geometry concerned with ascertaining lengths, areas, and volumes.

### 1. Lines and Angles

### 2. Triangle

### 3. Concurrent Lines in Triangle

- Angle Bisectors of Triangle
- Perpendicular Bisectors of Sides of Triangle
- Altitudes of Triangle
- Medians of Triangle