Example image of eyePlorer eyePlorer map for 'Perpendicular': Adjacent angle Angle Congruence (geometry) Geometry Line (geometry) Orthogonality Plane Adjective Noun Line segment Degree (angle) Radian Cartesian coordinate system Grade (slope) Compass and straightedge constructions Circle Distance Euclidean geometry Parallel postulate Vertical angles Reciprocal Unicode Tangential and normal components Altazimuth mount Altitude (triangle) Axial tilt Center of percussion Circular surface Corduroy road Discordant coastline Filter paper Glenopolar angle Harp Kamatz Koppa gate Oblique reflection Parallel axis theorem Perpendicular axis theorem Pickaxe Prolate trochoidal mass spectrometer Roads in Windsor, Ontario Shear stress Six degrees of freedom St Nicholas' Church, Kenilworth Surface normal Syon Abbey Tarry point Ultraparallel theorem Bias (textile) Brahmagupta theorem