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.