The term is used especially when the pieces form a right angle.

Notice how its surface forms an angle, like a writing table.

It forms an angle of 40 to the course sailed.

The door was opened, and it formed a right angle to the doorway.

It formed an acute angle such as is never found in nature.

Once the board breaks, fold it back to form a right angle.

Turn out your feet equally, so as to form a right angle with each other.

They form an angle from 10-60 at the base.

In plan they form a right angle at the edge of the former rickyard.

About fifty people were collected at the angle formed by the end of the lake.