What is a right angle?

A right angle is the angle you make with a quarter turn, and it measures exactly 90°. Right angles are found at the corners of squares, rectangles, books and most rooms, and are often marked with a small square drawn in the corner.

Examples

• The corner of a piece of paper is a right angle.
• A clock's hands make a right angle at 3 o'clock.
• Two right angles together make a straight line (180°).

Quick facts

• A right angle is exactly 90°, a quarter of a full turn.
• An angle smaller than a right angle is acute; a larger one, up to 180°, is obtuse.