# Angles

## Perpendicular- At an angle of 90° to a given line (or plane or surface).

**Purple dictionary** (perpendicular) sat on the book shelf at **90°** angle.

**NOTE:**

Purple dictionary is perpendicular to the book shelf.

**Example 1**

The towers are perpendicular to the road of the bridge.

**Example 2**

Although the blue line is on an incline, the red line is still at 90° to it and so is perpendicular to the blue line.

**Example 3**

The sides of a cube are perpendicular to each adjoining side.

**Example 4**

Railway sleepers are laid perpendicular to the track.