Question 1

A truss is a frame that is usually three-dimensional and made of structural shapes.

Accepted Answer

A truss is typically a two-dimensional framework of straight pieces that form triangular units. The two-dimensional nature of trusses means they are designed for strength in a single plane, although they can be assembled to support three-dimensional structures.

Question 2

The point view of a line describes the inclination of a line in relation to the horizon.

Accepted Answer

The term "point of view" does not describe the inclination of a line in relation to the horizon. The correct term for this concept is "slope" or "gradient," which measures the steepness, incline, or grade of a line in the coordinate system.

Question 3

A fold line is represented by a thin, black line, and must be located in that plane.

Accepted Answer

A fold line is typically represented by a dashed or dotted line, not a thin, black line, and it indicates where the paper or material should be folded, not necessarily located in a specific plane.

Question 4

A fold line is drawn like a hidden line.

Accepted Answer

A fold line is typically drawn as a long, thin solid line, whereas a hidden line is represented by a dashed line to indicate edges not directly visible.

Question 5

The bearing and grade, or bearing and slope refers to the exact position of a fold line.

Accepted Answer

The bearing and grade (or slope) typically refer to the direction and steepness of a slope, respectively, not to the position of a fold line.

Question 6

Trusses are usually used in pairs or in multiples.

Accepted Answer

Trusses are often used in pairs or multiples to provide structural support over wide spans, such as in bridges, roofs, and floors, distributing loads efficiently.

Question 7

In order to find an edge view of a plane, a true-length line must be located in that plane.

Accepted Answer

To find an edge view of a plane, a line of true length within that plane is necessary because it establishes a reference for orienting the plane perpendicular to the line of sight, thereby revealing the plane's edge in true length.

Question 8

Pitch and bevel are indicated in a similar manner.

Accepted Answer

Pitch and bevel are both indicated by a number followed by a letter. The number indicates the size of the pitch or bevel, and the letter indicates the type of pitch or bevel.

Question 9

Notations are like footnotes.

Accepted Answer

Notations are brief explanatory notes added to a text or diagram, similar to footnotes which provide additional information or clarification.

Question 10

Azimuth bearing indicates the percent at which a line is angled.

Accepted Answer

Azimuth bearing indicates the direction of a line from a reference direction, usually north, measured in degrees from 0° to 360°, not a percentage of angle.

Question 11

The term cuts and fills refers to earth being excavated for highways.

Accepted Answer

Cuts and fills refer to the process of excavating earth to create a level path for highways or railways, where "cuts" are areas where the earth is removed, and "fills" are areas where the earth is added.

Question 12

Descriptive geometry is used by drafters, designers, and engineers because it graphically shows the solution to problems dealing with points, lines and planes, and their relationship in space.

Accepted Answer

Descriptive geometry is a branch of geometry that allows for the representation of three-dimensional objects in two dimensions, by using a set of techniques that help in visualizing the spatial relationships between objects. It is indeed used by drafters, designers, and engineers to solve problems related to the positioning and intersection of geometric shapes in space.

Question 13

Methods of assembling truss joints include welding, riveting, and bolting.

Accepted Answer

These are common methods used to assemble truss joints, each offering different advantages in terms of strength, cost, and application suitability.

Question 14

Notations are important because they are used to keep track of all views and points in space.

Accepted Answer

Notations are used to keep track of all views and points in space, making them essential for understanding and communicating spatial relationships.

Question 15

A vector is a directed line segment that in computer graphics is defined by its two end points.

Accepted Answer

In computer graphics, a vector is typically defined by its origin point and a direction (and magnitude), not by its two endpoints.

Question 16

The first step to determining the visibility of two intersecting lines (which of the two lines is closer) is to project the exact crossover point of the lines to an adjoining view.

Accepted Answer

Projecting the exact crossover point of the intersecting lines to an adjoining view allows for a clear determination of their spatial relationship, including which line is closer in the perspective of the viewer. This is a common practice in technical drawing and computer graphics to resolve visibility issues.

Question 17

Space diagrams and force diagrams are used in truss analysis to determine the forces in the members of a truss.

Accepted Answer

Space diagrams represent the geometry of the structure, showing the arrangement of members in space, while force diagrams (also known as free-body diagrams) are used to illustrate the forces acting on individual members, allowing for the calculation of those forces during truss analysis.

Question 18

A contour line on a plot or a map is a line at a constant elevation on the surface of the earth, above sea level.

Accepted Answer

Contour lines are used on maps to represent paths of constant elevation, indicating the height above sea level of every point along the line.

Question 19

When projecting a plane into another view, you must first find at least four points in the plane and project each point into the next view.

Accepted Answer

To project a plane into another view, you only need to project three non-collinear points from the plane into the next view, as three points are sufficient to define a plane.

Question 20

The significance of contour lines being close together on a map is steep terrain.

Accepted Answer

Contour lines that are close together on a map indicate steep terrain because they represent a rapid change in elevation over a short distance.

Quiz 10: Descriptive Geometry