Of or pertaining to right angles or perpendicular lines.
Related Terms 
DIAGRAM ON THE PLANE OF THE CELESTIAL MERIDIAN
A theoretical orthographic view of the celestial sphere from a point outside the sphere and over the celestial equator. The great circle appearing as the outer limit is the loca

ORTHOGRAPHIC CHART
A chart on the orthographic map projection.

PLAN
1. An orthographic drawing or view on a horizontal plane, as of an instrument, a horizontal section, or a layout. 2. A largescale map or chart of a small area, generally showing at increased scale a portion of the chart on which it is placed.

POLAR ORTHOGRAPHIC MAP PROJECTION
An orthographic map projection having the plane of the projection perpendicular to the axis of rotation of the earth, in this projection, the geographic parallels are full circles, true to scale, and the geographic meridians are straight lines.

PERSPECTIVE MAP PROJECTION
A map projection produced by the direct projection of the points of the ellipsoid (used to represent the earth) by straight lines drawn through them from some given point. The projection is usually made upon a plane tangent to the ellipsoid at the end of the diameter joining the point of projection and the center of the ellipsoid. The plane of projection is usually tangent to the ellipsoid at the center of the area being mapped. he analytical expressions that determine the elements of the projection. If the point of projection is at the center of the ellipsoid, a gnomonic map projection results; if it is at the point opposite the plane’s point of tangency a stereographic map projection; and if at infinity (the projecting lines being parallel to each other), an orthographic map projection. Most map projections are not perspective. Also called GEOMETRIC MAP PROJECTION.

PERPENDICULAR AXIS THEOREM
Atheorem which states that the sum of the moments of inertia of a plane lamina about any two perpendicular axes in the plane of the lamina is equal to the moment of inertia about an axis through their intersection perpendicular to the lamina.

ORTHOTROPIC
Having elastic properties such as those of timber, that is, with considerable variations of strength in two or more directions perpendicular to one another.

ONEWAY SLAB
A concrete slab in which the reinforcing steel runs perpendicular to the supporting beams, that is, one way.

OFFSET SCREWDRIVER
A screwdriver with the blade set perpendicular to the shank for access to screws in otherwise awkward places.

NORMAL STRESS
The stress component at a point in a structure which is perpendicular to the reference plane.
