Chapter 1

Question 1

Conjecture

Answer 1

an unproven statement that is based on a pattern or observation

Question 2

Inductive Reasoning

Answer 2

Looking for patterns and making conjectures is part of a process called inductive reasoning

Question 3

Counterexample

Answer 3

an example that shows a conjecture is false

Question 4

Undefined Terms

Answer 4

terms that cannot be mathematically defined using other words

Question 5

Point

Answer 5

no dimension, represented by a dot

Question 6

line

Answer 6

one dimension, extends without end and is represented by a line with two arrowheads

Question 7

Plane

Answer 7

two dimensions, represented by a shape that looks like a floor or wall and extends without end

Question 8

Postulates

Answer 8

statements that are accepted without further justification

Question 9

Postulate 1 and 2

Answer 9

Through any two points there is exactly one line Through any three points not on a line there is exactly one plane

Question 10

Collinear points

Answer 10

points that lie on the same line

Question 11

Coplanar points

Answer 11

points that lie on the same plane

Question 12

coplanar lines

Answer 12

lines that lie on the same plane

Question 13

Segment

Answer 13

(A-B): consists of the endpoints A and B and all points on AB in between A and B

Question 14

Ray

Answer 14

A–>B consists of the endpoint A and all points on AB that lie on the same side of A as B

Question 15

they “intersect”

Answer 15

figures that have any points in common

Question 16

intersection

Answer 16

two or more figures is the point or points that the figures have in common

Question 17

Postulate 3 “Intersection of two lines”

Answer 17

If two lines intersect, then their intersection is a point

Question 18

Postulate 4 “Intersection of two planes”

Answer 18

If two planes intersect, then their intersection is a line

Question 19

Coordinate

Answer 19

the real number that corresponds to a point is the coordinate of the point

Question 20

Distance

Answer 20

the absolute value of the difference of the coordinates of A and B AB is also called the length of A-B

Question 21

Postulate 5 “Segment Addition” Postulate 6 “Angle addition postulate”

Answer 21

If B is between A and C then AC = AB + BC. If AC = AB + BC, then B is between A and C. If P is in the interior of angle RST, then the measure of angle RST is the sum of the measures of angle RSP and PST

Question 22

Congruent segments

Answer 22

segments that have the same length Denoted by tick marks Symbol for indicating congruence is “≅” for now ill use =~

Question 23

Angle

Answer 23

consists of two rays that have the same endpoint

Question 24

Sides

Answer 24

The rays of the angle

Question 25

Vertex

Answer 25

the endpoint of the angle name of an angle

Question 26

Degrees

Answer 26

the measure of an Angle denoted by ° The measure of

Question 27

Congruent angles

Answer 27

Two angles that have the same measure denoted by =~

Question 28

Classifying angles by their measures

Answer 28

Acute angle, Obtuse angle, Right angle, Straight angle measure is between 0° and 90° measure is between 90° and 180° measure is 90° measure is 180°