Geometry Vocabulary

1
Geometry Vocabulary
an exact location in space
Point
. B
A straight path that goes on forever in both
directions
Line
A and B are any 2 points on the line
2
A straight path that goes on forever in one
direction
Ray
Starts at A and goes through B
A straight path that has two endpoints
Line segment
A flat surface that goes on forever in all
directions
Plane
plane ABC
3
Intersecting lines
Lines that cross at one point
Perpendicular lines
Lines that cross at right angles
Lines (in a plane ) that never cross
Parallel lines
4
Angles
is formed when 2 lines or rays intersect
Angle
A
B
C
the point where the 2 lines or rays intersect in
an angle
Vertex
N
5
an angle whose measure is less than 90 degrees
Acute angle
Obtuse angle
an angle whose measure is between 90 and 180
degrees
Straight angle
an angle whose measure is exactly 180 degrees
6
Right angle
an angle whose measure is exactly 90 degrees
Complementary angles
Two angles whose measures add up to 90 degrees
600
300
Two angles whose measures add up to 180 degrees
Supplementary angles
1300
500
7
Vertical angles
Two angles across from each other when 2 lines
cross
They are always congruent!
Adjacent angles
Two angles next to each other
They share a side and a vertex