Orthogonal Projection

A Projection of a figure by parallel rays. In such a projection, tangencies are preserved. Parallel lines project toparallel lines. The ratio of lengths of parallel segments is preserved, as is the ratio of areas.

Any Triangle can be positioned such that its shadow under an orthogonal projection is Equilateral. Also, the Medians of a Triangle project to the Medians of the image Triangle. Ellipses project to Ellipses, and anyEllipse can be projected to form a Circle. The center of an Ellipse projects to the center of the imageEllipse. The Centroid of a Triangle projects to the Centroid of its image. Under an Orthogonal Transformation, the Midpoint Ellipse can be transformed into aCircle Inscribed in an Equilateral Triangle.

Spheroids project to Ellipses (or Circle in the Degeneratecase).

• Augmented Tridiminished Icosahedron
• Augmented Truncated Cube
• Augmented Truncated Dodecahedron
• Augmented Truncated Tetrahedron
• Aureum Theorema
• Aurifeuillean Factorization
• Ausdehnungslehre
• Authalic Latitude
• Autocorrelation
• Automorphic Function
• Automorphic Number
• Automorphism
• Automorphism Group
• Autonomous
• Autoregressive Model
• Auxiliary Circle
• Auxiliary Latitude
• Auxiliary Triangle
• Average
• Average Absolute Deviation
• Average Function
• Average Seek Time
• Semisecant
• Semisimple
• Semisimple Algebra