EQUILATERALA polygon with sides of equal
ERRORThe difference between an observed or
computed value of a quantity and the true value
of the quantity. Errors are of two classifications:
accidental errors and systematic errors.
ERROR OF CLOSUREThe amount by which
the value of a quantity obtained by surveying
operations fails to agree with another value of the
same quantity held fixed from earlier
determinations or with a theoretical value of the
EXPONENTA small number or symbol placed
above and to the right of a mathematical quantity
to indicate the number of times the quantity
is to be multiplied by itself; for example,
EXTENSION LINESThin, unbroken lines used
to extend dimensions beyond the outline of a view
so they can be more easily read.
FINITE DISTANCEA defining measurable
FIRST ANGLE PROJECTIONMultiview
projection commonly used in Europe in which the
top view is below the front view and the right side
of the object, as shown in the front view, is toward
the left side view of the object.
FORESHORTENINGThe reduction in length
of receding lines in an oblique projection that
allows the object to appear to be optically correct.
FORESIGHT 1. A sight on a new survey point,
made in connection with its position determina-
tion; or a sight on a previously established point
to close a circuit. 2. In leveling, a foresight
(FS) is the rod reading on a rod held on a
point whose elevation is being determined. (See
FORMATThe systematic arrangement of
drawing sheet space
to standardize the location
of required information.
FRACTIONA division indicated by placing the
dividend (numerator) over the divisor (denomi-
nator) wit h a line between them.
Proper Fraction: 3/4
Improper Fraction: 3/2 = 1 1/2
Mixed Fraction: 1 7/8
FRENCH CURVEInstrument used to draw
smooth irregular curves.
FREEHAND DRAFTINGAny drawing in
which the pen or pencil is guided solely by hand.
FRUSTUM OF A CONEThe portion of a cone-
shaped solid next to the base that is formed by
cutting off the upper part by a plane parallel to
FRUSTUM OF A PYRAMIDThe portion of
a pyramid-shaped solid next to the base that is
formed by cutting off the top by a plane parallel
to the base.
FULL SECTIONA sectional view that passes
entirely through the object.
GEODETIC DATUMDatum that forms the
basis for the computation of horizontal-control
surveys in geodetic surveying. It consists of five
quantities: the latitude and the longitude of an
initial point, the azimuth of a line from this point,
and two constants necessary to define the
GEOMETRYThat branch of mathematics that
investigates the relations, properties, and measure-
ment of solids, surfaces, lines, and angles; it also
deals with the theory of space and of figures in
GRADE (GRADIENT)The rate of rise and fall
or slope of a line; generally expressed in percent
or as a ratio.
GRAPH PAPERGridded paper in a variety of
scales and patterns used for plotting, sketching,
GRIDA network composed of two sets of
equidistant parallel lines intersecting at right
GRID COORDINATESThe numbers and
letters of a coordinate system that designate a
point on a grid.
GUARD STAKEA stake driven near a hub,
usually sloped with the top of the guard stake over
the hub. The guard stake protects, and its
markings identify, the hub.