Linked from

The 11 pages that link to Right angle, each with the reason it gives.

• Degree (angle)Related: It provides a familiar benchmark equal to one quarter of a full turn.

• RectangleRelated: Four right angles distinguish rectangles from most other quadrilaterals.

• SquareRelated: Four right angles are part of the square’s defining conditions.

• GradianRelated: One right angle is exactly 100 gradians.

• Fagnano's problemRelated: The perpendicularity of altitudes creates the angle relations central to the orthic triangle's perimeter.

• De Gua's theoremRelated: Three edges meeting at the distinguished vertex form pairwise right angles.