orthographic projection

normal edge, point

A [a] [b] is a line perpendicular to a plane of projection. It appears as a [c] on that plane of projection and as a true-length line on adjacent planes of projection.

normal, inclined, oblique

A [a] surface is parallel to a plane of projection. An [b] surface is perpendicular to one plane of projection but inclined (tipped) to adjacent planes. An [c] surface is tipped to all principal planes of projection.

true

A center line takes precedence over a hidden line.

point

A corner, or _______, is the common intersection of three or more surfaces.

perpendicular, parallel, foreshortened

A plane surface that is [a] to a plane of projection appears on edge as a straight line. If it is [b] to the plane of projection, it appears true size. If it is angled to the plane of projection, it appears [c] or smaller than its actual size.

true

A point located in a drawing can represent two things: 1) a vertex, 2) the point view of an edge.

true, false

A sketch or drawing should contain only the views needed to clearly and completely describe the object. These minimally required views are referred to as the required views.

true

A straight visible or hidden line in a drawing or sketch has three possible meanings: 1) an edge between two surfaces, 2) the edge view of a surface, 3) the limiting element of a curved surface.

projection

A view of an object is called a _______.

true

A visible line always takes precedence over and covers up a centerline or hidden line when they coincide in a view.

inclined edge, foreshortened

An [a] [b] is parallel to one plane of projection but inclined to adjacent planes. It appears as a true-length line on the plane to which it is parallel and as a [c] line on adjacent planes.

oblique plane

An [a] [b] is tipped to all planes of projection.

true

An oblique edge appears foreshortened and as an angled line in every view.

principle views

Any object can be viewed from six mutually perpendicular directions. These are called the six [a] [b].

true

Any principal view of a 3D object shows only two of the three principal dimensions; the third is found in an adjacent view.

true

Because an oblique edge is not parallel to any projection plane, it cannot appear true length in any standard view.

true

Because it is not perpendicular to any projection plane, an oblique edge cannot appear as a point in any standard view.

first

Europe, Asia, and many other places use the _______-angle projection system.

similar

If a flat surface is viewed from several different positions, each view will show the same number of sides and a _______ shape.

orthographic, orthographic

In [a] projection, rays (or projectors) from all points on the edges or contours of the object extend parallel to each other and perpendicular to the plane of projection. The word [b] means "at right angles".

multiview projection

In engineering and other fields, a complete and clear description of the size and shape of an object is necessary to be sure that it is manufactured exactly as the designer intended. To provide this information about a 3D object, a number of systematically arranged views are used. The system of views is called [a] [b].

two, right, top, best

Many objects only need [a] views to clearly describe their shape. If an object requires only two views, and the left-side and right-side views show the object equally well, use the [b]-side view. If an object requires only two views, and the top and bottom views show the object equally well, choose the [c] view. If only two views are necessary and the top view and right-side view show the object equally well, choose the combination that fits [d] on your paper.

single

Often, a _______ view supplemented by a note or by lettered symbols is all that is necessary to completely describe the object.

dashed

On an orthographic drawing, thick, dark lines represent features of the object that are directly visible. _______ lines represent features that would be hidden behind other surfaces.

glass box

One way to understand the standard arrangement of views on the sheet of paper is to envision a [a] [b].

frontal plane, horizontal plane, profile plane

Specific names are given to the planes of projection. The front view is projected to the [a] [b]. The top view is projected to the [c] [d]. The side view is projected to the [e] [f].

false

The centerline pattern is composed of three dashes: one short dash on each end with a long dash in the middle.

true

The centerline pattern is used to show the axis of symmetry for a feature or part, indicate a path of motion, show the location for bolt circles and other circular patterns.

dividers, scale, miter line

The depth dimensions in the top and side views must correspond point-for-point. You can transfer dimensions between the top and side views with [a], a [b], or by using a 45 degree [c] [d].

edge

The intersection of two plane surfaces of an object produces an _______, which shows as a straight line in the drawing.

third

The standard published in ANSI/ASME Y14 3M2003 is common in the United States, where _______-angle projection is used.

true

The three principal dimensions of an object are width, height, and depth.

true

The three regular views are the top, front, and right-side views because they are the views most frequently used.

third, first

There are two main systems used for projecting and unfolding the views (glass box): [a]-angle projection, which is used in the United States, Canada, and some other countries, and [b]-angle projection, which is used primarily in Europe and Asia.

projection symbols

To avoid confusing a first and third-angle projection drawing, international [a] [b] have been developed to distinguish between the two systems.

serious, worst

To draw a view out of place is a [a] error and is generally regarded as one of the [b] mistakes in drawing.

surface, plane

To effectively create and interpret multiview projections, you have to consider the elements that make up most solids. [a] form the boundaries of solid objects. A [b] (flat) surface may be bounded by straight lines, curves, or a combination of the two.

edge

To transfer a dimension from one view to a related view (a view that shares that dimension), measure from a plane that shows an _______ in both views.

vertically, horizontally

Using the American National Standard arrangement of views, the top, front, and bottom views align [a]. The rear, left-side, front, and right-side views align [b].

every

When edges are parallel to one another on the object, they will appear as parallel lines in _______ view, unless they align one behind the other.

folding lines

When envisioning the glass box, think of all planes except the rear plane as being hinged to the frontal plane. The rear plane is usually hinged to the left-side plane. Each plane folds out away from the frontal plane. The representation of the hinge lines of the glass box in a drawing are known as [a] [b].

width, height

When the glass box is unfolded, the front, top, and bottom views all line up vertically and are the same [a]. The rear, left-side, front, and right-side views all line up horizontally and are the same [b].

depth

_______ is shown in the left-side, top, right-side, and bottom views.

height

_______ is shown in the rear, left-side, front, and right-side views.

width

_______ is shown in the rear, top, front, and bottom views.