Geometry- Chapter 1 vocab
between
for any two points A and B on a line, there is another point C between A and B if and only if A,B, and C are collinear and AC+CB=AB
perpendicular
lines that form right angles
midpoint
the point halfway between the endpoints of the segment
precision
the precision of any measurement depends on the smallest unit available on the measuring tool
space
a boundless three dimensional set of all points
polygon
a closed figure whose sides are all segments
regular polygon
a convex polygon in which all sides are congruent and all angles are congruent
plane
a flat surface made up of points
point
a location on a line
line segment
a measure part of a line consists of two points called endpoints and all of the points between them
construction
a method of creating geometric figures without the benefit of measuring tools
linear pair
a pair of adjacent angles whose noncommon sides are opposite rays.
ray
a part of a line
exterior
a point that is neither on the angle nor in the interior of the angle
concave
a polygon for which there is a line containing a side of the polygon that also contains a point in the interior of the polygon
convex
a polygon for which there is no line that contains both a side of the polygon and a point in the interior of the polygon
n-gon
a polygon with n sides
angle bisector
a ray that divides an angle into two congruent angles
segment bisector
a segment, line, or plane that intersects a segment at its midpoint
degree
a unit of measure used in measuring angles and arcs
Acute Angle
an angle with a degree measure less than 90
right angle
an angle with a degree measure of 90
obtuse angle
an angle with degree measure greater than 90 and less than 180
betweenness of points
any two real numbers a and b there is a real number n between a and b such that a<n<b
vertex
common endpoint
collinear points
on the same line
coplanar
points that line on the same plane
sides
rays of an angle
relative error
the ratio of the half-unit difference in precision to the entire measure, expressed as a percent
perimeter
the sum of the lengths of the sides of the polygon
Adjacent angles
two angles that lie in the same plane, have a common vertex, and a common side, but no common interior points
complementary angles
two angles whose measures have a sum of 90
supplementary angle
two angles with measures that have a sum of 180
vertical angles
two nonadjacent angles formed by two intersecting lines.
Angle
two noncollinear rays that have a common endpoint
opposite rays
two rays BA and BC such that B is between A and C
congruent
when segments have the same measure
undefined terms
words that are not formally explained by means of more basic words and concepts
