point
the geometric figure formed at the intersection of two distinct lines
line
the geometric formed by two points. the straight path connecting two points and extending beyond the points in both directions
plane
a flat surface extending in all directions, any three collinear points lie on one and only one plane
ray
a part of a line starting at a particular point and extending infinitely in one direction
line segment
all points between two given points
midpoint
the point halfway between two given points
collinear
lying on the same line
coplanar
lying in the same plane
bisector
a line segment, line, or plane that divides a geometric figure into two congruent halves
perpendicular
at a 90-degree angle. have slopes that are negative reciprocals
parallel
two distinct coplanar lines that do not intersect, have the same slope
angle
two rays sharing a common endpoint.
vertex
a corner point of a geometric figure
adjacent angle
two angles in a plane which share a common vertex and a common side but do not overlap
vertical angles
angles opposite of one another at the intersection of two lines. congruent
linear pair
a pair of adjacent angles formed by intersecting lines
complementary
two acute angles that add up to 90- degrees
supplementary
two angles that add up to 180-degrees
postulate
a statement that is accepted as true without proof
theorem
assertion that can be proved true using the rules of logic
acute angle
an angle that has a measure of less than 90- degrees
obtuse angle
an angle that has a measure of more than 90- degrees and less than 180-degrees
right angle
a 90-degree angle
straight angle
a 180- degree angle