Unit 1 - Introduction to Geometry - Definitions

Question 1

Definition of Point

Diagram: .P
Notation: P

Answer 1

A location that has neither width nor length

Question 2

Definition of Line (3)

Answer 2

1. Infinite set of points
2. Extend infinitely in 2 directions
3. Line Has No Width

Question 3

Definition of Collinear

Answer 3

Points on the same line

Question 4

Definition of Plane

Answer 4

1. A flat surface
2. Made up of Points
3. Extends infinitely in all directions
4. 1 Plane is created by 3 Points

Question 5

Definition of Coplanar

Answer 5

Points of the same plane

Question 6

Other than three points, what also creates a plane?

Answer 6

The intersection of two lines

Question 7

What happens when two planes intersect? (2)

Answer 7

1. Creates a line of intersection.
2. Points found on this intersection are now collinear

Question 8

Definition of Line Segment (2)

Answer 8

1. A MEASURABLE part of aline
2. Consists of two endpoints

Question 9

Definition of Length of a Segment

Answer 9

The distance from two endpoints
Ex: AB = dist (A,B)

Question 10

Definition of Ray (3)

Answer 10

1. Consists of one endpoint
2. All points extends into a line
3. In notation, the end point is listed first

Question 11

Definition of Property of Betweenness

Answer 11

A point is only between two points if two parts equals to the whole

Ex: Point M is between Points P and Q if PM + MQ = PQ

Question 12

Definition of Midpoint (3)

Answer 12

1. A Point
2. Between Two Endpoints
3. Divides segment into two equal halves

Question 13

Definition of Segment Bisector

Answer 13

1. Segment/Line/Plane
2. Intersects through the midpoint

Question 14

Definition of Perpendicular Lines

Answer 14

1. Lines/Line Segments/Rays
2. Intersects
3. Forms Right Angles

Question 15

Definition of Perpendicular Bisector

Answer 15

Perpendicular intersection through the midpoint

Question 16

Definition of Opposite Rays

Answer 16

1. Two rays with a common endpoints
2. Forms a line of 180 degrees

Question 17

Definition of Angle

Answer 17

1. Two non - collinear rays
2. Share a common endpoint

Question 18

Definition of Vertex

Answer 18

Common endpoint of an angle

Question 19

Definition of Right Angle

Answer 19

90 degree Angle

Question 20

Definition of Acute Angle

Answer 20

Angle between 0 and 90 degrees

Question 21

Definition of Obtuse Angle

Answer 21

Angle between 90 and 180

Question 22

Definition of Angle Bisector

Answer 22

Ray that divides an angle into congruent angles

Note: The angle measure will be 1/2 of the original value ofthe angle

Question 23

What are the sides of an angle?

Answer 23

Rays

Question 24

When three or more lines intersect at a common point, the lines are _______

Answer 24

Concurrent

Question 25

The point where three lines intersect is called the

Answer 25

Point of Concurrency

Question 26

The point of concurrency of the perpendicular bisectors of a triangle is the

Answer 26

CIRCUMCENTER

Question 27

Where is the circumcenter for obtuse triangles?

Answer 27

OUTSIDE the triangle

Question 28

Where is the circumcenter of a right triangle?

Answer 28

At the midpoint of the hypotenuse

Question 29

What is the circumcenter the center of?

Answer 29

The circumscribed circle

Question 30

What is the equation for the Sum of interior Angles of a Polygon?

Answer 30

180 (n-2)

Question 31

The point of concurrency of the angular bisectors of a triangle is the ________

Answer 31

Incenter

Question 32

What is notation for distance? (3)

Answer 32

1. AB = __
2. dist (A, B) = __
3. |AB| = ___