Geometry Unit 1
angle
a figure formed by two rays with a common endpoint
plane
a flat surface that has no thickness and extends forever
euclid
a greek mathematician and teacher who lived in the 3rd century BC
segment bisector
a line, line segment, or ray that intersects a line segment at its midpoint
point
a location in space that has neither size nor dimension
construction
a method of creating a geometric figure that is mathematically precise by using a compass and straightedge
coordinate
a number that corresponds to a point
coordinate plane
a plane that is divided into four regions by a horizontal line, called the x-axis, and a vertical line, called the y-axis
midpoint
a point that bisects a segment into two congruent segments
line segment
a portion of a line consisting of two points and all the points between them
ray
a portion of a line that starts at one point and extends forever in only one direction
dimension
a property of space consisting of the measure of distance in one direction
angle bisector
a ray that bisects an angle into two congruent angles
postulate
a statement accepted as true without proof as a basis for reasoning; another name for an axiom
line
a straight path that has no thickness and extends forever
axiom
a universally accepted principle which does not require proof
straight angle
an angle whose measure is 180 degrees and whose rays form a straight line
right angle
an angle whose measure is exactly 90 degrees
acute angle
an angle whose measure is greater than 0 degrees and less than 90 degrees
obtuse angle
an angle whose measure is greater than 90 degrees but less than 180 degrees
bisect
dividing into two equal or congruent parts
euclidean geometry
geometry based on the axioms of euclid
solid geometry
geometry that deals with three-dimensional objects
plane geometry
geometry that deals with two-dimensional objects
differential geometry
geometry that uses calculus to study how geometric functions respond to changing variables
congruent
having the same shape and size
congruent segments
line segments that have the same length
quadrant
one of four regions into which a coordinate plane is divided
linear pair of angles
pair of adjacent angles whose noncommon sides are two opposite rays that form a straight line
collinear points
points that lie on the same line
coplanar points
points that lie on the same plane
interior of an angle
the set of points between the two sides of an angle
exterior of an angle
the set of points outside an angle
space
the unlimited region in which all things exist
supplementary angles
two angles in which the sum of their measures equals 180 degrees
complementary angles
two angles in which the sum of their measures equals 90 degrees
adjacent angles
two angles that share a common vertex and one common side but have no common interior points
vertical angles
two nonadjacent angles formed by two intersecting lines
undefined terms
terms used to describe basic geometric figures that are fundamental to all other geometric figures and, as such, cannot be defined by using other geometric terms
geometry
the branch of mathematics that deals with the study of geometric figures, such as points, lines, planes, and solids, and the deduction of properties, measurements, and relationships of those figures
vertex
the common endpoint of the rays of an angle
endpoint
the point at either end of a line segment or the point at the start of a ray
origin
the point where the x-axis and the y-axis intersect on a coordinate plane
ordered pair
the set of coordinates that indicates the position of a point on a coordinate plane