Geometry Unit One

Question 1

point

Answer 1

a place in space

Question 2

line

Answer 2

made up of points that extend infinitely in both directions

Question 3

number line

Answer 3

when a # is assigned to each point on a line

Question 4

line segments

Answer 4

line but with definite beginning and end

Question 5

ray

Answer 5

begin at endpoint but extends infinitely in the other direction

Question 6

angle

Answer 6

two rays that share and endpoint

Question 7

vertex

Answer 7

where lines intersect

Question 8

triangle

Answer 8

3 sides, 3 angles

Question 9

union

Answer 9

U, adds “sets” together

Question 10

intersection

Answer 10

upside down U, finds the overlap of the sets

Question 11

collinearity

Answer 11

points that lie on the same line

Question 12

triangle inequality

Answer 12

the sum of the lengths of any two sides of a triangle is always greater than the length of the third

Question 13

do assume from diagrams4

Answer 13

• straight lines/angles
• collinearity
• betweenness of points
• relative positions

Question 14

don’t assume from diagrams3

Answer 14

• right angles
• congruent segments/angles
• relative sizes of segments/angles

Question 15

theorem

Answer 15

mathematical statement that can be proved

Question 16

theorem 1

Answer 16

if two angles are right angles, then they are congruent

Question 17

theorem 2

Answer 17

if two angles are straight angles, then they are congruent

Question 18

bisector

Answer 18

point/line/ray/segment that divides a segment/angle into 2 congruent segments

Question 19

midpoint

Answer 19

bisection point

Question 20

trisector

Answer 20

point/line/ray/segment that divides a segment/angle into 3 congruent segments

Question 21

counterexample

Answer 21

example that proves a conclusion false

Question 22

deductive structure

Answer 22

system of thought in which conclusions are justified by means of previously assumed/proved statements

Question 23

undefined term

Answer 23

fairly clear idea of a term Ex: point, line

Question 24

postulate

Answer 24

unproved assumption

Question 25

definition

Answer 25

states the meaning of a term/idea ex: acute/right/obtuse angle

Question 26

conditional statement

Answer 26

"if p, then q"

Question 27

hypothesis

Answer 27

the "if" part of a conditional statement

Question 28

conclusion

Answer 28

the "then" part of a conditional statement

Question 29

converse

Answer 29

"if q, then p"(usually false)

Question 30

negation

Answer 30

the opposite of a statement

Question 31

inverse

Answer 31

" ˜p, the ˜q"(usually false)

Question 32

contrapositive

Answer 32

"if ˜q, then ˜p" (usually true)

Question 33

theorem3

Answer 33

if a conditional statement is true, then the contrapositive of the statement is also true

Question 34

probability

Answer 34

#winners/#possibilities

Question 35

chain rule

Answer 35

series of conditional statements that are connected