Download Unit 2 Vocabulary with definitions - Wynter Bounds

Unit 2 –Angles Vocabulary
Study Guide
1. Point- The smallest unit in Geometry used to determine a specific location.
2. Line-An infinite series of connected points
3. Plane-A series of connected points that form an infinitely large flat surface.
4. Ray- Part of a line that has one endpoint and extends infinitely in the other
direction.
5. Segment- Part of a line that has 2 endpoints
6. Angle- a figure formed by 2 rays that share a common endpoint
7. Vertex- The point of an angle where the 2 endpoints of each ray meet.
8. Right Angle- An angle whose measure is equal to 90⁰.
9. Obtuse Angle- An angle whose measure is larger than 90⁰, but smaller than
180⁰.
10.Acute Angle- An angle whose measure is less than 90⁰.
11.Straight Angle- An angle whose measure is equal to 180⁰.
12.Vertical Angles- Congruent angles that are formed when two lines cross,
and are located opposite of each other.
13.Adjacent Angles- 2 angles that share a common side and common vertex.
14.Complementary Angles- Two angles whose sum is 90⁰.
15.Supplementary Angles- Two angles whose sum is 180⁰.
16.Linear Pair- Two adjacent angles whose sum is 180⁰.
17.Compass- An instrument that is used in constructions to draw circles and
arcs with a given radius.
18.Protractor-An instrument that is used to measure angles.
19.Parallel Lines- Lines that have the same slope and will never intersect.
20.Perpendicular Lines- Lines that intersect and form right angles.
21.Transversal- A line that intersects two or more other lines.
22.Slope- The ratio of the vertical change to horizontal change of a line.
23.Construction- To create geometric figures using a compass and straight
edge.
24.Angle Bisector- A line or ray that is drawn in such a way that it separates an
angle into two congruent angles.
25.Segment Bisector- A line, ray, or segment that is drawn in such a way that it
separates a segment into 2 equal parts at the midpoint.
26.Perpendicular Bisector- A line, ray, or segment that is drawn in such a way
that it separates a segment into 2 equal parts and forms right angles at the
midpoint.
27.Postulate- A geometric statement that is self-evident and does not require
proof before using it as a rule for solving problems.
28.Theorem-A geometric statement that requires proof before it can be used
as a rule for solving problems.
29.Proof- Using detailed mathematical reasoning to demonstrate that a
proposition must be true.
30. Midpoint – The point located in the center of a segment that separates the
segment into two congruent parts.
31. Collinear – Points that are on the same line.