A right-angle marker is a small square drawn at the vertex of an angle to indicate
that it is a right angle , measuring sides of the square
lie along the rays forming the angle ,
so only the other two short line segments need to
be drawn.
It is commonly used to mark perpendicular lines and the right angle of a right
triangle (Marecek et al. 2020, §9.3; Kirk 2023, §10.1).
See also Angle Marker ,
Perpendicular ,
Right Angle
Explore with Wolfram|Alpha
References Key Curriculum Press. "Angle Markers." The Geometer's Sketchpad Reference Center. https://referencecenter.dynamicgeometry.com/gsp-reference-center/angle_markers.htm . Kirk,
D. "Points, Lines, and Planes." §10.1 in Contemporary Mathematics.
Houston, TX: OpenStax, 2023. https://openstax.org/books/contemporary-mathematics/pages/10-1-points-lines-and-planes . Marecek,
L.; Anthony-Smith, M.; and Mathis, A. H. "Use Properties of Angles, Triangles,
and the Pythagorean Theorem." §9.3 in Prealgebra 2e. Houston, TX:
OpenStax, 2020. https://openstax.org/books/prealgebra-2e/pages/9-3-use-properties-of-angles-triangles-and-the-pythagorean-theorem .
Cite this as:
Weisstein, Eric W. "Right-Angle Marker."
From MathWorld https://mathworld.wolfram.com/Right-AngleMarker.html
Subject classifications
(Kirk 2023, §10.1). It is also called a right-angle
symbol. Two sides of the square
lie along the rays forming the angle,
so only the other two short line segments need to
be drawn.
