Download Unit 1 Vocabulary-Formal Definitions

1. Point Dot that names
a location and
has no size.
2. Line
Straight path
that extends
infinitely in
both directions.
3. Plane
Flat surface
that extends
infinitely in all
directions
4. Collinear Points that lie
on the same
line. (2 points
are always
collinear)
5. Coplanar Things that lie
on the same
plane.
6. Segment Part of a line
with 2
endpoints.
7. Ray
Part of a line
that starts at an
endpoint and
extends
infinitely in one
direction.
8. Angle Figure formed
by 2 rays with a
common
endpoint.
9.Vertex Common
endpoint of the
sides of an angle
or shape
Two angles that
10.
Adjacent share a
Angles common vertex
and a common
side, but no
common
interior points.
11. Linear Pair of adjacent
Pair angles that
together form a
straight line.
12. Acute Angle with
Angle measure less
than 90°.
13. Right
Angle
Angle with
measure
equal to 90°
14. Obtuse Angle with
Angle measure
greater than
90° and less
than 180°
15. Straight Angle with
Angle measure
equal to 180°
16.
Complementary
Angles
Angles whose
sum is 90°
17.
Angles
Supplementary whose sum
Angles
is 180°
18.
Point that
Midpoint lies exactly
in the
middle of a
segment.
19.
Point that lies
Between inside of two
other points on
a line, segment
or ray.
20.
Line or point
Segment that cuts a
Bisector segment into 2
equal parts
21.
Angles with
Congruent the exact
Angles
same
measure.
22. Angle Ray or line that
Bisector divides an angle
into 2 equal
(congruent)
angles.