Chapter 2: Lines & Angles

Question 1

Collinear points

Answer 1

points that lie on the same line

Question 2

Noncollinear points

Answer 2

points that do not lie on the same line

Question 3

Postulate 1: Two points determine

Answer 3

a unique straight line

Question 4

Postulate 2: Three noncollinear points determine

Answer 4

a unique plane

Question 5

Line segment

Answer 5

part of a line consisting of two points, called end points, and the set of all points between them

Question 6

Congruent line segments

Answer 6

line segments that have equal lengths

Question 7

Postulate 3: The Ruler Postulate: (a) To every point on line

Answer 7

there corresponds exactly one real number called its coordinate

Question 8

Postulate 3: The Ruler Postulate: (b) To every real number

Answer 8

there corresponds exactly one point on the line

Question 9

Postulate 3: The Ruler Postulate: (c) To every pair of points

Answer 9

there corresponds exactly one real number called the distance between the points

Question 10

Postulate 3: The Ruler Postulate: (d) The distance between two points

Answer 10

is the absolute value of the difference between their coordinates

Question 11

Betweenness of Points

Answer 11

If F,G, and H, are collinear, and if FG + GH = FH, then G is between F and H

Question 12

Ray

Answer 12

A part of a line consisting of a given point, called the end point, and the set of all points on one side of the end point.

Question 13

Angle

Answer 13

The union of two rays having the same end point. The end point is called the vertex of the angle; the rays are called the sides of the angle.

Question 14

Congruent angles

Answer 14

angles that have equal measures

Question 15

Postulate 4: The Protractor Postulate: (a) The rays in a half rotation (180 degrees) can be numbered

Answer 15

so that to every ray there corresponds exactly one real number called its coordinate

Question 16

Postulate 4: The Protractor Postulate: (b) To every real number from 0 to 180

Answer 16

there corresponds exactly one ray

Question 17

Postulate 4: The Protractor Postulate: (c) To every pair of rays there corresponds exactly one real number called

Answer 17

the measure of the angle that they determine

Question 18

Postulate 4: The Protractor Postulate: (d) The measure of an angle is

Answer 18

the absolute value of the difference between the coordinates of its rays

Question 19

Betweenness of Rays

Answer 19

(I cannot type a line with an arrow, so it will say “ray” instead)
(ray) PS is between (ray) PQ and (ray) PR if point S lies in the interior of <QPR.

Question 20

Right angle

Answer 20

an angle with a measure of 90

Question 21

Acute angle

Answer 21

an angle with a measure of less than 90

Question 22

obtuse angle

Answer 22

an angle with a measure of greater than 90 (and less than 180)

Question 23

midpoint of a line segment

Answer 23

the point that divides the line segment into two congruent line segments

Question 24

Segment bisector

Answer 24

A bisector of (line) AB is any line, ray or line segment which passes through the midpoint of (line) AB.

Question 25

Angle Bisector

Answer 25

(ray) OR is the bisector of

Question 26

Addition Property: If equals are added to equals,

Answer 26

the results are equal: If a = b, then a + c = b + c

Question 27

Subtraction Property: If equals are subtracted from equals,

Answer 27

the results are equal: If a = b, then a - c = b - c

Question 28

Multiplication Property: If equals are multiplied by equals,

Answer 28

their products are equal: If a = b, then ac = bc

Question 29

Division property: If equals are divided by nonzero equals,

Answer 29

their quotients are equal: If a = b, then a/c = b/c as long as c is not equal to 0

Question 30

Substitution Property: If a = b, then either a or b may be substituted

Answer 30

for the other in any equation

Question 31

Transitive Property: If two quantities are equal to the same quantity,

Answer 31

then they are equal to each other: If a = b and b = c, then a = c.

Question 32

Reflexive Property

Answer 32

Any quantity is equal to itself: a = a.

Question 33

Symmetric Property

Answer 33

The positions of the expressions on either side of an equals sign may be reversed: If a = b, then b = a.